In his career he also played for Slavia Sofia, Turkish Bursaspor, Greek AEK Athens as well as for the Portuguese clubs Marítimo and Salgueiros.

Iliev earned his first cap with Bulgaria in a friendly match against Turkey on 21 August 1991 in Stara Zagora.

Under his management in the 2009–10 season, Beroe won a historical first Bulgarian Cup and consequently achieved a participation in the UEFA Europa League qualification stages.

In mid May 2014, Iliev held final talks to become the manager of Angolan club Inter Luanda.

Iliev came close to securing European club football for the team, as the "smurfs" finished in 5th place in the standings during the 2015/2016 A PFG.

[7] In early 2017, Iliev signed a contract to manage newly promoted Altai Semey from the Kazakhstan Premier League, but stepped down in February 2017, as the club eventually did not receive a license for the top division.

[10] On 1 November 2023, Iliev was officially announced as the new manager of Bulgaria while remaining in charge of his club team Cherno More.