Samir Dorkavandi, a prayer leader, was on his way to mosque Saturday evening when he was shot and wounded by an unidentified man on a motorbike.
The cleric was immediately taken to a nearby hospital in Ahvaz where he unwent surgery, ISNA said.
Ahvaz, centre of the oil-rich province of Khuzestan bordering Iraq, has in the last two years been scene of violent unrest and fatal bombings by Iranian-Arab separatists.
Tehran has accused the United States and British agents of links to the unrest, which both Washington and London deny.
Three men were hanged earlier this month in Ahvaz for involvement in bombings, and according to local judiciary officials, other men linked to the incident are awaiting execution.
