In 1939 Yugoslavia received 73 Me-109 E-3's in exchange for iron, copper and chrome ore. However the aircraft were grounded most of the time due to a lack of spares. The Yugoslav pilot were not happy with their new fighters. There were a lot of landing accidents.
When the Germans invaded in April 1941 the Yugoslav Air Force put up a fight but could do little to repel the invaders.

By the end of the war 17 109's were left. These were stored until 59 more were acquired from Bulgaria. The new Yugoslav Air Force used a mix of G-2, G-6, G-10 and G-12 aircraft. The aircraft were used until about the middle of 1952.

Me-109 E-3's prior to delivery to Yugoslavia (Source: AJ Press Monografie 50: Messerschmitt Me-109 Cz. 6)

Messerschmitt Me-109 E-3 (Source: Die Deutsche Luftfahrt, Willy Messerschmitt)

Yugoslavian Me-109 E-3 1940 (Source: AJ Press Monografie 50: Messerschmitt Me-109 Cz. 5)

Captured Me-109 G-10 used by Yugoslavian partisans 1945 (Source: Ventura decal sheet)

Me-109 G-12 acquired from Bulgaria. Note the Erla hood on the cockpit (Source: Wings of Fame 11)

Me-109 G-6 displayed in the Yugoslavian Aviation Museum (Source: Wings of Fame 11)