 In 1957 he was appointed as a United Nations expert for the Mexican government and to the economic commission for Latin America.Fournastié was a professor at the Institut d'Etudes Politiques de Paris until his retirement in 1978.He became professor (Directeur d'études) at the VIth section of the École Pratique des Hautes Études (later EHESS)  in 1951, and from 1960 he held the chair of Economics and Industrial Statistics at CNAM.