During the Serbo-Bulgarian War in 1885 Stefan Toshev was a commander of 2nd company of the 3rd Vidin Regiment,[1] and was in charge of the Tran position.

He took part in the battle of Slivnitsa, the fight at Tran (3 November), the repulse of the Serbian Morava Division.

He fought bravely in the battle of Tri Ushi and the attack of Meka tsrav (7 November).

During the First Balkan War (1912–1913) Stefan Toshev and his division took part in the offensive of the Bulgarian Army in the Thracian theatre of operation.

In October 1923 he led the "Narodna Priznatelnost" committee whose aim was to give assistance for the victims of the Communist insurgents during the September Uprising.