[4] After participating in the student protests against the 10 March 1952 coup d'état which brought dictator Fulgencio Batista to power, Piñeiro's family sent him to study business management at Columbia University in New York.
He discovered that he was under police surveillance, and decided that it was better to leave for the Eastern Sierra Maestra mountain range and join the guerrillas headed by Fidel Castro.
After the Cuban Revolution, Piñiero was appointed Deputy Minister of the Interior and the head of the Technical Viceministerio, the body that would be later responsible for gathering intelligence and developing strategies to expand communism in Latin America.
Subsequently, he was appointed Chief of Personnel and Inspection, a position that included responsibilities for the Intelligence Service and the recently created Policía Rebelde, which was a predecessor of Castro's Revolutionary Police.
During the Bay of Pigs Invasion, Piñeiro was deputy to Ramiro Valdés Menéndez, head of G-2 (Seguridad del Estado, or state security).
[5] On June 6, 1961, he was appointed Deputy Minister of the Interior and head of the so-called Technical Viceministerio, the body that would be later responsible for gathering intelligence and developing strategies to expand communism in Latin America.