The International Federation of Human Rights (FIDH), the Baha'i International Community (BIC) and the Iranian League for Human Rights (LDDHI) said Ahmadinejad must tackle discrimination against religious and ethnic minorities, women, and halt incitement to hatred.
"By coming to the Durban Review Conference, President Ahmadinejad signals a commitment to the conference's goals of eliminating all forms of discrimination and intolerance," said Diane Ala'i, the BIC's representative at the UN in Geneva.
"His first move on returning home, then, should be to address the severe discrimination and persecution that have flourished under his tenure," she added.
Ahmadinejad is the most prominent head of state scheduled to address the opening of the UN review conference on Monday, which is being boycotted by the United States, Israel, Canada, Australia and the Netherlands.
His virulent anti-Israel statements and comments casting doubt on the Holocaust have prompted fears that his speech could overshadow the primary aim of the conference, to take stock of racial discrimination, xenophobia and intolerance around the world.
The rights groups said religious discrimination was widespread in Iran, notably affecting Baha'is, Christians, Jews, Sufis, Sunni Muslims, and other minorities, through arbitrary arrests, intimidation and harassment.
They also accused Iranian government-controlled media of fomenting hatred against Bahai's, and warned that repression against activists belonging to ethnic minorities including the Kurds was "rising dramatically".
"Human rights have sharply deteriorated in Iran under the presidency of Mahmoud Ahmadinejad. Discrimination against ethnic and religious minorities, as well as against women, are of grave concern," said Karim Lahidji of LDDHI.
The human rights groups called on governments taking part in the conference, as well as the media, to hold Ahmadinejad accountable for violations in Iran.
