diff --git a/src/Lexer/Lexer.cpp b/src/Lexer/Lexer.cpp
index c54cda7..535fd97 100644
--- a/src/Lexer/Lexer.cpp
+++ b/src/Lexer/Lexer.cpp
@@ -208,10 +208,15 @@ shared_ptr<Token> Lexer::nextToken() {
     if (token != nullptr)
         return token;
 
-    token = matchInteger();
+    token = matchIntegerDec();
     if (token != nullptr)
         return token;
 
+    token = matchIntegerHex();
+    if (token != nullptr)
+        return token;
+
+
     // type
     token = match(TokenKind::TYPE, "bool", true);
     if (token != nullptr)
@@ -260,17 +265,39 @@ shared_ptr<Token> Lexer::match(TokenKind kind, string lexme, bool needsSeparator
     return token;
 }
 
-shared_ptr<Token> Lexer::matchInteger() {
+shared_ptr<Token> Lexer::matchIntegerDec() {
     int nextIndex = currentIndex;
 
-    while (nextIndex < source.length() && isDigit(nextIndex))
+    while (nextIndex < source.length() && isDecDigit(nextIndex))
         nextIndex++;
     
     if (nextIndex == currentIndex || !isSeparator(nextIndex))
         return nullptr;
     
     string lexme = source.substr(currentIndex, nextIndex - currentIndex);
-    shared_ptr<Token> token = make_shared<Token>(TokenKind::INTEGER, lexme, currentLine, currentColumn);
+    shared_ptr<Token> token = make_shared<Token>(TokenKind::INTEGER_DEC, lexme, currentLine, currentColumn);
+    advanceWithToken(token);
+    return token;
+}
+
+shared_ptr<Token> Lexer::matchIntegerHex() {
+    int nextIndex = currentIndex;
+
+    // match 0x
+    if (nextIndex > source.length()-2)
+        return nullptr;
+
+    if (source.at(nextIndex++) != '0' || source.at(nextIndex++) != 'x')
+        return nullptr;
+
+    while (nextIndex < source.length() && isHexDigit(nextIndex))
+        nextIndex++;
+    
+    if (nextIndex == currentIndex || !isSeparator(nextIndex))
+        return nullptr;
+    
+    string lexme = source.substr(currentIndex, nextIndex - currentIndex);
+    shared_ptr<Token> token = make_shared<Token>(TokenKind::INTEGER_HEX, lexme, currentLine, currentColumn);
     advanceWithToken(token);
     return token;
 }
@@ -278,7 +305,7 @@ shared_ptr<Token> Lexer::matchInteger() {
 shared_ptr<Token> Lexer::matchReal() {
     int nextIndex = currentIndex;
 
-    while (nextIndex < source.length() && isDigit(nextIndex))
+    while (nextIndex < source.length() && isDecDigit(nextIndex))
         nextIndex++;
     
     if (nextIndex >= source.length() || source.at(nextIndex) != '.')
@@ -286,7 +313,7 @@ shared_ptr<Token> Lexer::matchReal() {
     else
         nextIndex++;
     
-    while (nextIndex < source.length() && isDigit(nextIndex))
+    while (nextIndex < source.length() && isDecDigit(nextIndex))
         nextIndex++;
 
     if (!isSeparator(nextIndex))
@@ -329,11 +356,16 @@ bool Lexer::isWhiteSpace(int index) {
     return character == ' ' || character == '\t';
 }
 
-bool Lexer::isDigit(int index) {
+bool Lexer::isDecDigit(int index) {
     char character = source.at(index);
     return character >= '0' && character <= '9';
 }
 
+bool Lexer::isHexDigit(int index) {
+    char character = source.at(index);
+    return (character >= '0' && character <= '9') || (character >= 'a' && character <= 'f');
+}
+
 bool Lexer::isIdentifier(int index) {
     char character = source.at(index);
     bool isDigit = character >= '0' && character <= '9';
diff --git a/src/Lexer/Lexer.h b/src/Lexer/Lexer.h
index 0d756a8..b4cb848 100644
--- a/src/Lexer/Lexer.h
+++ b/src/Lexer/Lexer.h
@@ -18,14 +18,16 @@ private:
 
     shared_ptr<Token> nextToken();
     shared_ptr<Token> match(TokenKind kind, string lexme, bool needsSeparator);
-    shared_ptr<Token> matchInteger();
+    shared_ptr<Token> matchIntegerDec();
+    shared_ptr<Token> matchIntegerHex();
     shared_ptr<Token> matchReal();
     shared_ptr<Token> matchIdentifier();
     shared_ptr<Token> matchEnd();
     shared_ptr<Token> matchInvalid();
 
     bool isWhiteSpace(int index);
-    bool isDigit(int index);
+    bool isDecDigit(int index);
+    bool isHexDigit(int index);
     bool isIdentifier(int index);
     bool isSeparator(int index);
     void advanceWithToken(shared_ptr<Token> token);
diff --git a/src/Lexer/Token.cpp b/src/Lexer/Token.cpp
index 5c6700b..0980d69 100644
--- a/src/Lexer/Token.cpp
+++ b/src/Lexer/Token.cpp
@@ -37,7 +37,8 @@ vector<TokenKind> Token::tokensBinary = {
 };
 vector<TokenKind> Token::tokensLiteral = {
     TokenKind::BOOL,
-    TokenKind::INTEGER,
+    TokenKind::INTEGER_DEC,
+    TokenKind::INTEGER_HEX,
     TokenKind::REAL
 };
 
@@ -121,8 +122,10 @@ string Token::toString() {
 
         case TokenKind::BOOL:
             return "BOOL(" + lexme + ")";
-        case TokenKind::INTEGER:
-            return "INTEGER(" + lexme + ")";
+        case TokenKind::INTEGER_DEC:
+            return "INTEGER_DEC(" + lexme + ")";
+        case TokenKind::INTEGER_HEX:
+            return "INTEGER_HEX(" + lexme + ")";
         case TokenKind::REAL:
             return "REAL(" + lexme + ")";
         case TokenKind::IDENTIFIER:
diff --git a/src/Lexer/Token.h b/src/Lexer/Token.h
index c50c91f..617ef7e 100644
--- a/src/Lexer/Token.h
+++ b/src/Lexer/Token.h
@@ -35,7 +35,8 @@ enum class TokenKind {
     RETURN,
 
     BOOL,
-    INTEGER,
+    INTEGER_DEC,
+    INTEGER_HEX,
     REAL,
     IDENTIFIER,
     TYPE,
diff --git a/src/Parser/Expression.cpp b/src/Parser/Expression.cpp
index d5fd09d..1966f52 100644
--- a/src/Parser/Expression.cpp
+++ b/src/Parser/Expression.cpp
@@ -130,8 +130,12 @@ Expression(ExpressionKind::LITERAL, ValueType::NONE) {
             boolValue = token->getLexme().compare("true") == 0;
             valueType = ValueType::BOOL;
             break;
-        case TokenKind::INTEGER:
-            sint32Value = stoi(token->getLexme());
+        case TokenKind::INTEGER_DEC:
+            sint32Value = stoi(token->getLexme(), nullptr, 10);
+            valueType = ValueType::SINT32;
+            break;
+        case TokenKind::INTEGER_HEX:
+            sint32Value = stoi(token->getLexme(), nullptr, 16);
             valueType = ValueType::SINT32;
             break;
         case TokenKind::REAL: