Mansourian was born in Tehran. During his career he played for Singapore S-League S-League clubs Balestier Central (Balestier Khalsa FC) and Geylang United along with the Iranian club Esteghlal F.C. He moved to Greek club Xanthi in 1998 after Xanthi fans contributed to raise the amount of money needed to complete the transfer. He played for Skoda Xanthi for one and a half seasons, taking part in 23 games. In December 1999 Mansourian went to Apollon Athens for six months where he played seven games and scored once. After Apollon's relegation he continued his career in Germany's St. Pauli where he remained for two seasons. Finally he returned to Iran and Esteghlal FC where he was appointed as the teams captain.
Mansourian said farewell to professional football at the end of the 2007–08 season where Esteghlal became Hazfi Cup Champions.
He was head coach of Pas for four months in 2009. In August 2010, Afshin Ghotbi chose Mansourian as his assistant coach for the Iran national football team. After resignation of Ghotbi as head coach of national team, Mansourian was named as interim head coach until the appointment of Carlos Queiroz. He also coached Iran in a 1–0 win against Russia.