Prior to becoming a television star, Valdés was an extra in many films. The three brothers went on to become three of Latin America"s most well known comedians. He was the uncle of Mexican popular singer Cristian Castro.
Valdés participated in more than 50 Mexican films, specializing in hyperactive underdog characters.
He is likely best-remembered for playing Don Ramón in the hit television show The Chavo of 8. Valdés also appeared on Chespirito"s other hit show, El Chapulín Colorado, usually as Chapulín"s antagonist, the famous Tripaseca ("Dry Gut").
In some episodes, he portrayed a character named Super Sam, an English-speaking, money-thirsty superhero dressed as Superman, clearly mocking Uncle Sam and the relatively wealthy situation of United States, when compared to average Latin American countries, as well as criticizing the American colonialism. Both El Chavo and El Chapulín became major international hits across Latin America, Spain, the United States and other non-Spanish speaking countries, giving their entire cast international fame.
Ramón Valdés was no exception, he would be identified as Don Ramón (or as "Ron Damón") at many different countries he visited.
In Brazil, where the beloved character/actor (as the show itself) is culted by the 80"s and 90"s generation as a vintage masterpiece, he was known as Seu Madruga instead (literally: Mr Dawn, since Madruga is short for Madrugada, dawn), following the Portuguese dubbing for El Chavo del Ocho, which, in that country, is called simply Chaves. In 1979, he left Chespirito, but he returned to television a few years later, with fellow Chavo del Ocho and Chapulín Colorado cast member Carlos Villagrán in Federrico, also known as ¡Ah Quė Kiko!. Federrico found little success, however, and Ramón Valdés returned to work with Chespirito for a brief time in 1981.
Valdés and Villagrán were replaced by Raul "Chato" Padilla, who played Jaimito The Postman in the remaining Chavo del Ocho episodes.
Valdés also owned a circus, participating in circus acts. On 9 August 1988, Valdés died at age 64 after a battle with stomach cancer.