His 1st Provisional Government was in power from 15 May to 17 July 1974. As an independent, he chose cabinet members from widely divergent political parties and positions, including members of the then center-left Popular Democratic Party, the Socialist Party and even the Portuguese Communist Party and the Armed Forces Movement (MFA) officers. The ideological diversity of the government seems to be one of the main reasons why the government didn't last, being the other the calling for anticipated presidential elections before Constituent Assembly election, 1975. He was replaced by Colonel Vasco Gonçalves, a choice that Spínola would later regret. After leaving office, Palma Carlos was the national representative (mandatário) of general António Ramalho Eanes for the 1980 Presidential Elections.
He was married to Elina Júlia Chaves Pereira Guimarães (Lisbon, 1904 – 1991).