diff --git a/CMakeLists.txt b/CMakeLists.txt
index a0934b5..092df24 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -77,7 +77,7 @@ add_executable(unit_tests
         sources/APU/Instructions/ProgramFlow.cpp
         sources/APU/Operand.cpp
         sources/APU/Instructions/DecimalCompensation.cpp;
-        sources/APU/Instructions/MultiplicationDivision.cpp)
+        sources/APU/Instructions/MultiplicationDivision.cpp sources/APU/Instructions/16bitArithmetic.cpp)
 
 # include criterion & coverage
 target_link_libraries(unit_tests criterion -lgcov)
@@ -165,7 +165,7 @@ add_executable(ComSquare
         sources/APU/Instructions/ProgramFlow.cpp
         sources/APU/Operand.cpp
         sources/APU/Instructions/DecimalCompensation.cpp
-        sources/APU/Instructions/MultiplicationDivision.cpp)
+        sources/APU/Instructions/MultiplicationDivision.cpp sources/APU/Instructions/16bitArithmetic.cpp)
 
 target_compile_definitions(ComSquare PUBLIC DEBUGGER_ENABLED)
 
diff --git a/sources/APU/APU.cpp b/sources/APU/APU.cpp
index caa1165..32f22ec 100644
--- a/sources/APU/APU.cpp
+++ b/sources/APU/APU.cpp
@@ -184,6 +184,8 @@ namespace ComSquare::APU
 			return this->CLR1(this->_getDirectAddr(), 0);
 		case 0x13:
 			return this->BBC(this->_getDirectAddr(), 0);
+		case 0x1A:
+			return this->DECW(this->_getDirectAddr());
 		case 0x1F:
 			return this->JMP(this->_getAbsoluteAddrByX(), true);
 		case 0x20:
@@ -210,6 +212,8 @@ namespace ComSquare::APU
 			return this->CLR1(this->_getDirectAddr(), 1);
 		case 0x33:
 			return this->BBC(this->_getDirectAddr(), 1);
+		case 0x3A:
+			return this->INCW(this->_getDirectAddr());
 		case 0x3F:
 			return this->CALL(this->_getAbsoluteAddr());
 		case 0x40:
@@ -236,6 +240,8 @@ namespace ComSquare::APU
 			return this->CLR1(this->_getDirectAddr(), 2);
 		case 0x53:
 			return this->BBC(this->_getDirectAddr(), 2);
+		case 0x5A:
+			return this->CMPW(this->_getDirectAddr());
 		case 0x5F:
 			return this->JMP(this->_getAbsoluteAddr());
 		case 0x60:
@@ -262,6 +268,8 @@ namespace ComSquare::APU
 			return this->CLR1(this->_getDirectAddr(), 3);
 		case 0x73:
 			return this->BBC(this->_getDirectAddr(), 3);
+		case 0x7A:
+			return this->ADDW(this->_getDirectAddr());
 		case 0x7F:
 			return this->RETI();
 		case 0x80:
@@ -284,6 +292,8 @@ namespace ComSquare::APU
 			return this->CLR1(this->_getDirectAddr(), 4);
 		case 0x93:
 			return this->BBC(this->_getDirectAddr(), 4);
+		case 0x9A:
+			return this->SUBW(this->_getDirectAddr());
 		case 0x9E:
 			return this->DIV();
 		case 0xA0:
diff --git a/sources/APU/APU.hpp b/sources/APU/APU.hpp
index f9f883d..3e6b143 100644
--- a/sources/APU/APU.hpp
+++ b/sources/APU/APU.hpp
@@ -277,6 +277,17 @@ namespace ComSquare::APU
 		int MUL();
 		//! @brief Divide the 16-bit value YA by X, storing the quotient in A and the remainder in Y.
 		int DIV();
+
+		//! @brief Increment a word value.
+		int INCW(uint24_t addr);
+		//! @brief Decrement a word value.
+		int DECW(uint24_t addr);
+		//! @brief Add YA with a word value.
+		int ADDW(uint24_t addr);
+		//! @brief Subtract YA with a word value.
+		int SUBW(uint24_t addr);
+		//! @brief Compare YA with a word value.
+		int CMPW(uint24_t addr);
 	public:
 		explicit APU(std::shared_ptr<MemoryMap> &map);
 		APU(const APU &) = default;
diff --git a/sources/APU/Instructions/16bitArithmetic.cpp b/sources/APU/Instructions/16bitArithmetic.cpp
new file mode 100644
index 0000000..9ca5c61
--- /dev/null
+++ b/sources/APU/Instructions/16bitArithmetic.cpp
@@ -0,0 +1,77 @@
+//
+// Created by Melefo on 25/02/2020.
+//
+
+#include "../APU.hpp"
+
+namespace ComSquare::APU
+{
+	int APU::INCW(uint24_t addr)
+	{
+		uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
+		uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr)) + 1u;
+
+		this->_internalWrite(addr, value);
+		this->_internalWrite(addr2, value >> 8u);
+		this->_internalRegisters.n = value & 0x8000u;
+		this->_internalRegisters.z = !value;
+		return 6;
+	}
+
+	int APU::DECW(uint24_t addr)
+	{
+		uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
+		uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr)) - 1u;
+
+		this->_internalWrite(addr, value);
+		this->_internalWrite(addr2, value >> 8u);
+		this->_internalRegisters.n = value & 0x8000u;
+		this->_internalRegisters.z = !value;
+		return 6;
+	}
+
+	int APU::ADDW(uint24_t addr)
+	{
+		uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
+		uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr));
+		uint24_t result = this->_internalRegisters.ya + value;
+
+		this->_internalRegisters.v = (~(this->_internalRegisters.ya ^ value) & (this->_internalRegisters.ya ^ result)) & 0x8000u;
+		this->_internalRegisters.c = result > 0xFFFFu;
+		this->_internalRegisters.h = ((this->_internalRegisters.ya & 0x0FFFu) + (value & 0x0FFFu)) > 0x0FFFu;
+		this->_internalRegisters.z = !result;
+		this->_internalRegisters.n = result & 0x8000u;
+		this->_internalRegisters.ya = result;
+		return 5;
+	}
+
+	int APU::SUBW(uint24_t addr)
+	{
+		uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
+		uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr));
+		uint24_t result = this->_internalRegisters.ya - value;
+		uint16_t tmp = ((this->_internalRegisters.ya & 0x0F00u) - (value & 0x0F00u)) >> 8u;
+
+		if ((this->_internalRegisters.ya & 0x00FFu) < (value & 0x00FFu))
+			tmp--;
+		this->_internalRegisters.v = ((this->_internalRegisters.ya ^ value) & (this->_internalRegisters.ya ^ result)) & 0x8000u;
+		this->_internalRegisters.c = result <= 0xFFFFu;
+		this->_internalRegisters.h = tmp <= 0x000F;
+		this->_internalRegisters.z = !result;
+		this->_internalRegisters.n = result & 0x8000u;
+		this->_internalRegisters.ya = result;
+		return 5;
+	}
+
+	int APU::CMPW(uint24_t addr)
+	{
+		uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
+		uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr));
+		uint24_t result = this->_internalRegisters.ya - value;
+
+		this->_internalRegisters.z = !result;
+		this->_internalRegisters.n = result & 0x8000u;
+		this->_internalRegisters.c = this->_internalRegisters.ya >= value;
+		return 4;
+	}
+}
\ No newline at end of file
diff --git a/tests/APU/testAPUInstructions.cpp b/tests/APU/testAPUInstructions.cpp
index bdf0c8a..23dd1a8 100644
--- a/tests/APU/testAPUInstructions.cpp
+++ b/tests/APU/testAPUInstructions.cpp
@@ -768,4 +768,92 @@ Test(MultiplicationDivision, DIV)
 	result = apu->DIV();
 	cr_assert_eq(apu->_internalRegisters.y, 147);
 	cr_assert_eq(apu->_internalRegisters.a, 211);
+}
+
+//////////////////////////////////
+//								//
+// (XVI)16-bit Arithmetic tests //
+//								//
+//////////////////////////////////
+
+Test(XVIbitArithmetic, INCW)
+{
+	auto apu = Init().second.apu;
+	int result = 0;
+
+	apu->_internalWrite(apu->_internalRegisters.pc, 0x55);
+	apu->_internalWrite(0x55, 0xFF);
+	apu->_internalWrite(0x55 + 1, 0x22);
+	result = apu->INCW(apu->_getDirectAddr());
+	cr_assert_eq(result, 6);
+	cr_assert_eq(apu->_internalRead(0x55), 0x00);
+	cr_assert_eq(apu->_internalRead(0x55 + 1), 0x23);
+}
+
+Test(XVIbitArithmetic, DECW)
+{
+	auto apu = Init().second.apu;
+	int result = 0;
+
+	apu->_internalWrite(apu->_internalRegisters.pc, 0x55);
+	apu->_internalWrite(0x55, 0x00);
+	apu->_internalWrite(0x55 + 1, 0x23);
+	result = apu->DECW(apu->_getDirectAddr());
+	cr_assert_eq(result, 6);
+	cr_assert_eq(apu->_internalRead(0x55), 0xFF);
+	cr_assert_eq(apu->_internalRead(0x55 + 1), 0x22);
+}
+
+Test(XVIbitArithmetic, ADDW)
+{
+	auto apu = Init().second.apu;
+	int result = 0;
+
+	apu->_internalRegisters.ya = 0x4321;
+	apu->_internalWrite(apu->_internalRegisters.pc, 0x55);
+	apu->_internalWrite(0x55, 0x11);
+	apu->_internalWrite(0x55 + 1, 0x22);
+	result = apu->ADDW(apu->_getDirectAddr());
+	cr_assert_eq(result, 5);
+	cr_assert_eq(apu->_internalRegisters.ya, 0x6532);
+	cr_assert_eq(apu->_internalRegisters.n, false);
+	cr_assert_eq(apu->_internalRegisters.v, false);
+	cr_assert_eq(apu->_internalRegisters.h, false);
+	cr_assert_eq(apu->_internalRegisters.z, false);
+	cr_assert_eq(apu->_internalRegisters.c, false);
+}
+
+Test(XVIbitArithmetic, SUBW)
+{
+	auto apu = Init().second.apu;
+	int result = 0;
+
+	apu->_internalRegisters.ya = 0x4321;
+	apu->_internalWrite(apu->_internalRegisters.pc, 0x55);
+	apu->_internalWrite(0x55, 0x11);
+	apu->_internalWrite(0x55 + 1, 0x22);
+	result = apu->SUBW(apu->_getDirectAddr());
+	cr_assert_eq(result, 5);
+	cr_assert_eq(apu->_internalRegisters.ya, 0x2110);
+	cr_assert_eq(apu->_internalRegisters.n, false);
+	cr_assert_eq(apu->_internalRegisters.v, false);
+	cr_assert_eq(apu->_internalRegisters.h, true);
+	cr_assert_eq(apu->_internalRegisters.z, false);
+	cr_assert_eq(apu->_internalRegisters.c, true);
+}
+
+Test(XVIbitArithmetic, CMPW)
+{
+	auto apu = Init().second.apu;
+	int result = 0;
+
+	apu->_internalRegisters.ya = 0x2211;
+	apu->_internalWrite(apu->_internalRegisters.pc, 0x55);
+	apu->_internalWrite(0x55, 0x11);
+	apu->_internalWrite(0x55 + 1, 0x22);
+	result = apu->CMPW(apu->_getDirectAddr());
+	cr_assert_eq(result, 4);
+	cr_assert_eq(apu->_internalRegisters.z, true);
+	cr_assert_eq(apu->_internalRegisters.c, true);
+	cr_assert_eq(apu->_internalRegisters.n, false);
 }
\ No newline at end of file