At Tehran University, Mehdi Semsar entered the Faculty of Pharmacy and received his Ph.D. degree.

Mehdi Semsar's professional life in journalism began actually in 1949 when Kayhan contracted him as their parliamentary correspondent.

By translating approximately fifty historical, political and cultural books, Mehdi Semsar greatly contributed to younger Iranian generations' understanding of world affairs and Western civilization.

Most of these translations included a long preface written by himself and explaining the interest of the book, author, or historical period.

In 2007, Guity Elahi established the Omid Journalism Prize[1][2] in memory of her husband Mehdi Semsar.