[5] In his career at the UN, Benomar worked for the Office of the High Commissioner for Human Rights (OHCHR), the United Nations Development Programme (UNDP) and the Department of Political Affairs (DPA).

He has advised on conflict resolution issues in over 30 countries, including Yemen, Afghanistan and Iraq, where in 2004 he served as the Secretary-General's Envoy to support the National Dialogue Conference.

Benomar led the Office of the Special Envoy of the Secretary-General for Yemen, where he worked "to facilitate the combined efforts of the international community to promote a democratic transition in the country".

[11] In a statement delivered to the press following his final briefing on Yemen to the Security Council, Benomar condemned "systematic acts of obstruction" and warned against "interference and coercion from outside forces".

[13] Benomar warned that Yemen's conflict could become an “Iraq-Libya-Syria” scenario if either side pushes for control of the country, prompting the U.N. Security Council to threaten further measures if the hostilities do not end.

[14] The statement sparked outrage among the Saudis and their Gulf allies, who poured scorn on Benomar in the Arabic-speaking media.

[citation needed] Benomar has authored numerous publications over the course of his career dealing with governance, rule of law, constitution writing, and peace building.

[19] Benomar has also appeared on TV news programs on several networks, including CNN,[20] BBC,[21] and Al Jazeera.