Nigeria dominated possession in the Group F fixture at Arena da Baixada – particularly in the first half – but a disciplined defensive performance from the Iranians ensured the spoils were shared.
After a handful of early chances, the African nation failed to make the most of their pressure, seeing attacking moves fail in the final third time and again.
And Iran, whose best chance to score came courtesy of a first-half header from Reza Ghoochannejad, saw their persistence pay off as they held on for a point.
Argentina now lead the group by two points after their 2-1 win over Bosnia and Herzegovina on Sunday.
Nigeria named Fenerbahce frontman Emmanuel Emenike as their sole striker, but it was winger Victor Moses who got the first sight of goal, drilling a tame effort comfortably into the arms of goalkeeper Alireza Haghighi.
The Africa Cup of Nations champions had the ball in the back of the net from a corner in the eighth minute, but the whistle had already blown as Haghighi was somewhat fortuitously awarded a free-kick after a coming together with John Obi Mikel.
Iran were struggling to get a foothold in the match, and Ogenyi Onazi was next to fire a warning signal by sending the ball dribbling wide of the left-hand upright.
For all their possession, Nigeria were not working Haghighi hard enough in the Iranian goal, and Stephen Keshi was forced to bring Joseph Yobo on for Godfrey Oboabona on the half-hour mark after the defender had earlier landed awkwardly in an aerial challenge with Ghoochannejad.
Iran – growing in confidence as the half progressed - almost punished their opponents’ profligacy four minutes later when a Ghoochannejad header from a corner forced Vincent Enyeama into a reflex save.
Keshi threw on Shola Ameobi seven minutes into the second half in a bid to give Nigeria more cutting edge in the final third, but it continued to be a tale of frustration as clear-cut chances continued to elude his side.
Iran had never previously kept a clean sheet at the World Cup finals, and their defensive approach drew whistles and heckles from fans in the green and white Nigeria.
Goalscoring chances became an increasingly rare occurrence and Nigeria will see this as a huge chance wasted with matches against Bosnia and Herzegovina and Argentina to follow.
Iran’s next fixture is against group leaders Argentina on Saturday.
