Born in Blagoevgrad, Berbatov started out with his home-town club Pirin before joining CSKA Sofia as a 17-year-old in 1998. He was signed by Bayer Leverkusen of Germany in January 2001 and played in his first Champions League final 18 months later, coming on as a substitute in the 2002 UEFA Champions League Final, which Leverkusen lost 2–1 to Real Madrid.