"This resolution is unjust, unjustifiable and totally political, and has been approved despite the reticence of certain countries, under pressure from the United States," foreign ministry spokesman Ramin Mehmanparast said.
"The objective of this resolution is to put pressure on the Islamic Republic of Iran to divert attention from human rights violations in the West, in particular in the United States," he added.
The council voted by 22 to seven on Thursday to back a European led, US-backed resolution "to appoint a Special Rapporteur on the situation of human rights in the Islamic Republic of Iran."
The council regretted "the lack of cooperation on the part of the Islamic Republic of Iran" over recurring human rights abuses in the country following a UN General Assembly resolution adopted last December.
The United States, which had been pressing for the appointment, called it a "seminal moment".
Pakistan, which acted on behalf of Islamic states, as well as China, Cuba and Russia, were among seven countries to vote against the resolution, while 14 countries abstained. UN Secretary General Ban Ki moon last week regretted that the UN General Assembly report had highlighted a crackdown on women's rights activists, journalists and opposition activists.