After the start of the war in Croatia, Milan Mojsilović took part in fighting in the Banija region and remained stationed in the vicinity of the city of Petrinja as the commander of a tank platoon until the spring of the following year. In March and April in 1992 his tank unit again saw action in the Posavina region and the city of Derventa, where his armored vehicle was hit twice by the Croatian units stationed there. After JNA troops left Bosnia and Hercegovina in May 1992, he took up new duties in the units stationed in Serbia. Upon the commencement of the Kosovo war in March in 1999 he was transferred to the 243. mechanized brigade in Uroševac, where he fought and served as the chief operations officer.