After his graduation and marriage, El Mahdi worked for the Institute of Education for several years, and in 1960 was selected to participate in the Eleventh Session of the UNESCO General Conference in Paris.

Shortly afterwards, he was commissioned by the Government of Sudan to head the Institute of Education in Bakht er Ruda.

El Mahdi negotiated a temporary deal with the Saudi Minister of Education and came back to Sudan to work at the university in 1976.

However, a short time later, Eltayeb was dismissed by the Nimeiry administration and El Mahdi immediately resigned from his post and returned to Saudi Arabia.

The Minister of Education in Saudi Arabia recommended that it would be better if he was nominated by his own country, but the Nimeiry administration refused as he was an opponent of their regime.

[2] In the early 1980s, Mandour was selected to become the Vice-Chancellor of the Islamic University of Madinah, but fell ill shortly after he took up the post, and died in London in October 1981.