 | Warren Hull | ... | Mandrake the Magician |
 | Doris Weston | ... | Betty Houston |

| Al Kikume | ... | Lothar, Mandrake's Assistant |
 | Rex Downing | ... | Tommy Houston |
 | Edward Earle | ... | Dr. Andre Bennett |
 | Forbes Murray | ... | Professor Houston |
 | Kenneth MacDonald | ... | James Webster |
 | Don Beddoe | ... | Frank Raymond |
 | Dick Curtis | ... | Dorgan - Thug (Chs. 6-8) |
 | John Tyrrell | ... | Dirk, lead thug |
 | Stanley Brown | ... | Green, thug [Chs. 1, 2, 4] |
 | Beatrice Curtis | ... | Rest Home Nurse [Chs. 3,10] |
 | Robert Sterling | ... | Henchman |
 | Sam Ash | ... | George Regan, hypnotist [Chs. 3-5] |
 | Lester Dorr | ... | Gray, gas station thug [Chs. 8-9] |
 | Ernie Adams | ... | Henchman Brown [Chs. 2-3] |
 | Eddie Fetherston | ... | Rest Home Henchman [Chs. 10-11] |
 | Eddie Foster | ... | Ed, Blowdart Henchman [Chs. 1-3] |
| rest of cast listed alphabetically: |
 | Ernie Alexander | ... | Taxi Driver [Ch. 2] (uncredited) |
 | Harry Bernard | ... | Construction Camp Watchman [Chs. 4, 7] (uncredited) |
 | Stanley Blystone | ... | Henchman CX12 [Ch. 7] (uncredited) |
 | Buel Bryant | ... | Rest Home-Iron Works Henchman [Chs. 6-7] (uncredited) |
 | Budd Buster | ... | Construction Camp Henchman [Chs. 7-8] (uncredited) |
 | George Chesebro | ... | Henchman Baker [Chs. 7-8] (uncredited) |
 | Steve Clark | ... | Henchman (uncredited) |
 | Charles Dorety | ... | Mill River Inn Henchman [Chs. 4-5] (uncredited) |
 | Jerry Frank | ... | Harper Drive Henchman [Ch. 2] (uncredited) |
 | Kit Guard | ... | Powerhouse Henchman [Chs. 5-6, 8] (uncredited) |
 | Frank Hagney | ... | Henchman Harris [Chs. 8-9] (uncredited) |
 | Chuck Hamilton | ... | Bank Henchman [Ch. 5] (uncredited) |
 | Eddie Hart | ... | Henchman Williams [Ch. 7] (uncredited) |
 | Oscar 'Dutch' Hendrian | ... | Powerhouse Henchman [Chs. 5-6] (uncredited) |
 | Jerry Jerome | ... | Henchman Ward [Chs. 1, 3] (uncredited) |
 | Eddie Laughton | ... | Kidnap Henchman [Chs. 1-2] (uncredited) |
 | Tom London | ... | Mill River Inn Henchman [Chs. 4-5] (uncredited) |
 | Stanley Mack | ... | Roadster Henchman [Ch. 1] (uncredited) |
 | Knox Manning | ... | Narrator (voice) (uncredited) |
 | Pat McKee | ... | Dam Henchman [Chs. 8-9] (uncredited) |
 | Charles McMurphy | ... | Construction Foreman [Ch. 7] (uncredited) |
 | Frank Mills | ... | Gas Station Hitman [Ch. 9] (uncredited) |
 | Art Mix | ... | Iron Works Henchman [Chs. 6-7] (uncredited) |
 | Eddie Parker | ... | Henchman (uncredited) |
 | Ralph Peters | ... | S.S. Mohawk Steward-Henchman [Ch. 1] (uncredited) |
 | Rose Plumer | ... | Ship Passenger [Ch. 1] (uncredited) |
 | Cyril Ring | ... | Magic Mart Henchman [Ch. 4] (uncredited) |
 | Cy Schindell | ... | Bank Henchman [Ch. 5] (uncredited) |
 | Charles Sherlock | ... | Ship Henchman [Ch. 1] (uncredited) |
 | Reginald Simpson | ... | Parsons, the butler [Chs. 1-2, 7] (uncredited) |
 | Tom Steele | ... | Powerhouse Henchman [Chs. 5-6] (uncredited) |
 | Charles Sullivan | ... | Henchman-Driver [Ch. 3] (uncredited) |
 | Harry Tenbrook | ... | Streeter, lead powerhouse thug [Chs. 5-6] (uncredited) |
 | George Turner | ... | Apartment Raider [Ch. 4] (uncredited) |
 | Frank Wayne | ... | Henchman (uncredited) |
 | Blackie Whiteford | ... | Construction Camp Henchman [Chs. 7-8] (uncredited) |
 | Bud Wolfe | ... | Tower Henchman [Chs. 7-8] (uncredited) |
 | Bert Young | ... | Rest Home Henchman [Chs. 10-11] (uncredited) |
If you have stumbled upon this title and think you will see the hero of your comic book youth brought to the screen you will be disappointed. Mandrake has been shoehorned into a stock serial plot that could have used any one of a dozen heroes from Batman to Dick Tracy. Once again, a wonder invention cooked up by a solitary recluse in his basement is stolen from a mostly unguarded private residence and now the world is threatened. The police and the FBI are apparently helpless so it falls upon Mandrake to set things right. Alas, this Mandrake is a pale imitation of the comic wizard. The hypnotically gesturing magus of the comics has become a stage magician, doing card tricks on an ocean liner. Instead of confusing his enemies with black magic, he slugs it out with his fists, implausibly whipping two or three thugs at once, all without displacing his top hat.
This is not to say the serial isn't entertaining. But most will likely view it as a 70 year old curiosity rather than the exciting thriller it was meant to be. Whether you want to invest almost 4 hours of your life watching it is the question. Incidentally, the title music would later be reused in the Columbia serial "The Vigilante, Fighting Hero of the West" in a somewhat re-orchestrated form. The story, of course, would be recycled again and again.