Following the disputed 1984 election, and after Barletta's forced resignation, Delvalle served as President of Panama from 28 September 1985 until 26 February 1988.

In 1988, he attempted to remove Manuel Noriega as head of the armed forces but was himself deposed by the Legislative Assembly, going into hiding and eventually exile.

His uncle Max Delvalle was the first Jewish president in Latin America (both were members of Kol Shearit Israel Synagogue).

Instead, Noriega's allies in the Legislative Assembly voted on 22 February to oust Delvalle as president, appointing Education Minister Manuel Solis Palma in his place.

[4] Before his declaration against Noriega, Delvalle first made sure that his extended family was safe in the US embassy compound in Panama City.