Chibás vehemently opposed the rule of Fulgencio Batista in the 1950s, and he supported the anti-Batista struggle of Fidel Castro.
In July 1957, he signed the Sierra Manifesto, which proclaimed unity of the disparate anti-Batista groups.
He served various positions for Castro's government after the revolution, including railroad commissioner, trial judge and Minister of Finance.
He was a Major of the Cuban Army in 1960 when he decided to defect to the United States via a motor boat to Florida.
In 1960, he joined a group of former Castro aides in issuing a joint 3500-word manifesto calling for the overthrow of the Cuban leader.