Raul Costin

Costin is a product of the Național București youth academy making his first-team debut during the 2006–07 season against CFR Cluj coming on as a substitute in a 1–0 loss. Before his Național debut, he has played one season loaned to FC Sibiu during the 2005–06 season. In the 2008 summer, because of Progresul's (former Național) disaffiliation, he signed for Dacia Mioveni where he managed 12 goals, in 32 matches, finishing 6th with his team.

FC Vaslui

On 18 July 2009, he signed a three-year contract with SC Vaslui for an undisclosed fee. He made his first-team debut on 12 August, against Gaz Metan Mediaș coming as a substitute in a 2–1 win and he scored his first goal against Poli Iași in the Moldavian Derby, also in a 2–1 win. He helped his team reaching the Romanian Cup final after scoring the first goal, in the 4–0 win against FC Brașov in the semi-finals. On 15 April 2012 he scored an amazing goal against CS Mioveni in a 3–0 victory.

Simurq

In August 2013, Costin signed for Azerbaijan Premier League side Simurq. Costin made his debut for Simurq in their second game of the season, away to Khazar Lankaran on 11 August 2013, coming on as a 63rd-minute substitute for Stjepan Poljak. Costin's first goal for Simurq was the winning goal in the 89th minute against Inter Baku on 1 September 2013.

Universitatea Cluj

After one season at Simurq, Costin moved to Universitatea Cluj in June 2014.

Rapid București

Liga II: 2015–16