The Mad Doctor of Blood Island is a 1969 Filipino horror film, co-directed by Eddie Romero and Gerardo de Leon, and starring John Ashley, Eddie Garcia and Ronald Remy. It was the third in a series of four Filipino horror films produced by Romero and Kane W. Lynn known as the "Blood Island" series, which also included Terror Is a Man, Brides of Blood and Beast of Blood. Beverly Miller was associate producer on this film, and later went on to co-produce several other Filipino horror films. This film dared to go a step further than Brides of Blood in the nudity and gore department.