He has been capped for the Bulgaria national team, and was an unused substitute at the 1998 FIFA World Cup.

On 30 March 2010, CSKA Sofia coach Ioan Andone resigned, it was announced that the team will be trained by Adalbert Zafirov until the end of the season.

[1] Zafirov was appointed as head coach of Cherno More Varna in late September 2012, following the resignation of Stefan Genov.

[2] However, he was released from his duties in mid December 2012, despite winning his last game in charge of the team - 1–0 against Levski Sofia in the second leg of a Bulgarian Cup match.

In late December 2014, Zafirov became the manager of B PFG club Botev Vratsa,[3] but resigned on 27 April 2015.