In 1980, after the Communists had seized power in Afghanistan, Tarzi began working as International Civil Servant Diplomat for Organisation of Islamic Cooperation (OIC). From November 1979 until September 1986, Tarzi was the Senior Political Adviser at the Office of the Permanent Observer Mission of OIC to the United Nations, New York, United States of America. From November 1986 to November 1992, Tarzi was Ambassador, Deputy Permanent Observer of OIC to the United Nations, New York, United States of America.