The accident near the intersection of Sunset Cliffs Boulevard and Ladera Street was reported about 2:45 p.m., according to the San Diego Fire-Rescue Department.
Medics worked in vain to revive the victim, whose identity was not immediately available, before pronouncing him dead at the scene, SDFRD spokesman Lee Swanson said.
Lt. Andy Lerum with San Diego Lifeguards said the victim was a 65-year-old man from San Diego.
Lifeguards said the man fell 75 to 80 feet into the ocean. A passerby and his wife heard a loud "thud" and that's when lifeguards said the good Samaritan jumped into the water to pull the victim out before lifeguards arrived on scene.
Residents in and around Ocean Beach say these types of accidents happen far too often and called again for more signs cautioning people, as well as railings to go around the entire ledge.
Lt. Lerum told reporters the ground was unstable and there was an erosion problem that would defeat the purpose of putting up the railings. He advised people to keep back and stay at a safe distance away from the ledge of the cliffs as the ground is unstable and slippery with sand and rocks.