This one stars Lionel Atwill, and it probably won't come as much of a surprise to learn that he's the one playing the titular mad doctor. A self-appointed physician, Dr. Ralph Benson (Atwill) conducts an experiment on a man, the pseudo-scientist attempting to put his subject in suspended animation and them revive him. The man dies, and Benson flees, wanted for murder.
Benson changes his identity and books himself on a luxury cruise bound for New Zealand, but the ship catches fire and he is forced to get into a lifeboat with several other passengers and seek refuge on a nearby island. The natives of the island think that the white people are evil and plan to burn them alive, but Benson uses his medical knowledge to resuscitate a woman who they think has died (in reality, she has suffered a heart attack); the group is spared and Benson is declared a god.
Benson plans to stay on the island and continue his experiments, using the other passengers as guinea pigs, and so they decide to make a bid for freedom...
A routine B-movie elevated slightly above awful by Atwill, The Mad Doctor of Market Street offers very little to get excited about. The best scenes are of the panic-stricken passengers clambering over each other to get off the burning ship - almost everything that occurs on the island is predictable and dull low-budget nonsense using left-over jungle sets from other South Seas potboilers. At the end of the film, Atwill is roasted alive (off-screen) for being unable to revive a drowned native, while the other passengers are rescued by a search plane that spots them in the nick of time.
3.5/10, rounded up to 4 for Atwill.