Miss República Dominicana 1978 was held on 14 December 1977 at the Carnival of the Hyatt Hotel Fair in Santo Domingo, República Dominicana. Twenty-eight delegates competed; winner Raquel Josefina Jacobo Jaar (María Trinidad Sánchez) advanced to Miss Universo 1978, while Jennifer del Carmen Polanco Rivera (Puerto Plata) went to Miss Mundo 1978. Other semifinalists participated in various international pageants.