In his youth, he was an ardent follower of Fidel Castro and the Cuban Revolution. He was among the first generation of journalists to graduate after the triumph of the Revolution. From 1973-1976 he was the chief correspondent of the official Cuban press in Moscow. He also served as chairman of the pro-regime National Union of Writers and Artists (UNEAC). He was then known as "the Poet of the Revolution", and associated with the major cultural figures of communist Cuba.
In 1989 he left the National Union of Writers and Artists. On June 2, 1991 he signed the so-called "letter of the 10 intellectuals", a petition calling for the liberation of political prisoners and the holding of democratic elections. Since then, Rivero has been an outcast in Cuban society. In 1995, he founded Cuba Press, and became active in the Cuban independent journalism movement, publishing his works in newspapers in the United States and other countries.
In 1999 Rivero was awarded Columbia University's Maria Moors Cabot prize for International Journalism. The following year, he was named as one of the International Press Institute's 50 World Press Freedom Heroes of the past 50 years.
During the Cuban government's 2003 "Black Spring" crackdown on dissidents, Rivero was charged with "acting against Cuban independence and attempting to divide Cuban territorial unity", as well as with writing "against the government", organizing "subversive meetings" at his home, and collaborating with US diplomat James Cason. Rivero was convicted and sentenced to twenty years' imprisonment. He spent his first 11 months in a tiny one-man cell with no windows or any contact to the outside world. The arrest and imprisonment of Rivero was later defended by Cuban writer and culture minister Abel Prieto who argued that Rivero "was not arrested for his views, but for receiving US funding for his collaboration with a country that has besieged our island."  Rivero has asserted, in prison interrogations as well as in public, that all funds received consisted of fees for his articles, paid by the publishing media, not by governments or political organizations. His account of his life and his treatment by the Cuban government is given in his book "Proof of Contact".
- "World Press Freedom Heroes: Symbols of courage in global journalism". International Press Institute. 2012. Retrieved 26 January 2012.
- Proof of Contact: An Account of life in Cuba by Raul Rivero (2004) ISBN 0974247316