Silvera made guest appearances in numerous television series, mainly dramas and westerns, including "Studio One in Hollywood", "Alfred Hitchcock Presents", "Bat Masterson", "Thriller", "Riverboat", "The Travels of Jaimie McPheeters", "The Untouchables", and "Bonanza". In 1962 he portrayed Dr. Koslenko in "The Twilight Zone" episode "Person or Persons Unknown", opposite Richard Long. That year, he also played Minarii, a Polynesian man in the 1962 film "Mutiny on the Bounty", again starring Marlon Brando. In 1963, he starred with Dean Martin in movie "Toys in the Attic". Silvera was nominated for a Tony Award for Best Actor in a Play for playing Monsieur Duval in "The Lady of the Camellias".