The conservative-dominated assembly approved 18 of 21 nominees, propelling Mr Ahmadinejad into his second term at a time when the Islamic republic is battling its worst crisis since the hardliner's re-election in June.
The candidates who failed to secure the required majority of votes were the two other women proposed and the would-be energy minister.
In a move highlighting Iran's often maverick status in the world, nearly 80 per cent of the delegates approved Ahmad Vahidi - who is wanted by Argentina for a 1994 bombing in Buenos Aires - as defence minister.
Following the vote, Mr Vahidi said his election, which was by a far greater margin than any other, was a "decisive slap to Israel", an arch-enemy of Iran.
The first woman to join a cabinet in the Islamic republic will be Marzieh Vahid Dastjerdi, at the health ministry. A gynecologist and two-time former MP, Ms Dastjerdi, 50, was approved despite not having held an executive job in government.
Ms Dastjerdi described her selection as an important step for Iranian women.
"I think today women reached their long-standing dream of having a woman in the cabinet to pursue their demands," she told the parliamentary news service soon after the vote. "This is an important step for women and I hold my head high."
The other two women candidates, Sousan Keshvaraz and Fatemeh Ajorlou, fell short of the required number of votes to take over at the education ministry and at welfare and social security.
Oil ministry nominee Masoud Mirkazemi, who is set to head the crucial portfolio of OPEC's second-largest exporter, barely squeaked in after being harshly criticised by a powerful conservative MP.
The voting took place after five days of heated debate in which key nominees were strongly opposed by some MPs, yet approved in the end.
The confidence motion follows Mr Ahmadinejad's June re-election and subsequent protests that have divided Iran's ruling elite and powerful clerical groups and shaken the regime.
Source: The Australian