Kotkov died together with his friend and teammate Georgi Asparuhov in a traffic accident in the Vitinya Pass of the Balkan Mountains, en route to Vratsa.

For the Bulgaria national team, he had 26 caps and scored 12 goals, taking part in the 1966 FIFA World Cup in England.

Kotkov was known for his technique, pinpoint passing and skillful free kick taking.

On June 30 1971, Kotkov died in a car crash with teammate Georgi Asparuhov.

This biographical article related to association football in Bulgaria, about a forward, is a stub.