Santiago's career took off in the mid 1980s in Puerto Rico and Latin America, with his fame eventually spreading to Europe and the United States. He is asthmatic, which was a problem for him in certain places he toured, such as Mexico City. His best-known hit was Lluvia (Rain, not to be confused with Menudo's hit of the same name).
During the 1990s, Santiago's career went into decline, and he currently performs only at private events.