[1] In 2006, he joined Olympiakos Nicosia, but was replaced by Juan Ramon Rocha in October 2006.

[4] He resigned from his position on 26 March 2012, after enduring his first and only defeat with the club - a 0:1 home loss against Minyor Pernik.

In late July 2012, Kostov was appointed as the new head coach of Karpaty Lviv.

On 11 November 2015, Nikolay Kostov was appointed as the new head coach of Botev Plovdiv.

[6] After several years of coaching in Ukraine and Kazakhstan, on 13 June 2023, Kostov returned to Levski Sofia.