Yemen's national unity government, of which half the membership comes from the opposition, was sworn in on Saturday in the capital Sana'a, dpa reported.
Supporters of embattled President Ali Abdullah Saleh make up the other half of the cabinet, in accordance with conditions in a Gulf Cooperation Council plan (GCC) to end the conflict.
Vice President Abd Rabbo Mansour Hadi attended the ceremony at the presidential palace, where 33 ministers took the oath, led by Prime Minister Mohammed Basindawa.
On Wednesday, Hadi had announced the formation of the government, which is intended to end 11 months of political turmoil.
Hadi convened with the ministers promising to spare no efforts to deal with the crisis, the SABA news agency reported.
"The government is responsible to provide the suitable atmosphere to realize the national coalition," Hadi said, stressing the "role of the government to regain respect for the state and law."
Local and international reporters were not allowed to attend the oath ceremony at the request of Hadi. Some speculated that the ban is to avoid hurting the feelings of president Saleh.
The GCC-brokered plan forced Saleh to hand over power to Hadi in return for immunity from prosecution for him and his family. Saleh finally signed the deal in Saudi Arabia on November 23 after cancelling plans to do so at the last minute several times beforehand.
The GCC deal also calls for presidential elections to be pulled forward to February 21.
The secretary General of the GCC, Abdullatif Al-Zayani, arrived Saturday in Sana'a to evaluate the implementation of the power transfer deal.
Yemen has been gripped by an uprising against Saleh's regime since February.