After the success of the Revolution on 1 January 1959, Dorticós returned to Cuba and was appointed Minister of Revolutionary Laws in the cabinet headed by Fidel Castro. In that capacity, he played an important role in drafting revolutionary legislation such as the Agrarian Reform Act and the Fundamental Organic Law that supplanted the Constitution of 1940. After the resignation of President Manuel Urrutia, Dorticós was appointed President of Cuba by the Council of Ministers on 17 July 1959.