The legislators pledged further reforms to enhance democratic institutions, the rule of law, and the protection of human rights.
They also pledged to promote political, defense, and economic cooperation, and intensify the fight against corruption, organized crime, and terrorism.
The three nations hope to join NATO in 2008.
In Skopje, Macedonian President Branko Crvenkovski and his Croatian counterpart Stjepan Mesic signed a joint statement promising to "focus all their energy" on achieving their common strategic goal of membership in the European union and NATO.
After the meeting, Mesic said "we have to work hard to turn this region into an area of stability and prosperity."