 In 1999, when he was 19 years old, he was transferred to Levski Sofia, with whom he was Champion of Bulgaria in 1999–00 and won the 2000 Bulgarian Cup.Kolev made his competitive debut for Levski on 27 October 1999 against FC Iskar in the first round of the Bulgarian Cup, scoring three goals.In June 2000, he was loaned to Spartak Pleven.