A mad doctor uses patients at his isolated psychiatric institute as subjects in his attempts to create longevity by surgically installing an artificial gland in their skulls.
| Actor | Role |
|---|---|
 John CarradineDr. Charles Conway | Dr. Charles Conway |
 Myron HealeyMark Houston | Mark Houston |
 Allison HayesGrace Thomas | Grace Thomas |
 Marilyn BuferdDr. Sharon Gilchrist | Dr. Sharon Gilchrist |
 Tor JohnsonLobo | Lobo |
 Arthur BatanidesDanny Green | Danny Green |
 Sally ToddNatalie Andries | Natalie Andries |
| HHarry FleerHarry Jedrow | Harry Jedrow |
 Roy GordonDr. Loren Wright | Dr. Loren Wright |
 Guy PrescottPolice Captain George Reagan | Police Captain George Reagan |
 Raymond GuthPolice Officer Miller | Police Officer Miller |
| PPaul McWilliamsPolice Officer Ed | Police Officer Ed |
| GGloria PetroffScreaming Woman | Screaming Woman |
| KKarl JohnsonMonster in Basement (uncredited) | Monster in Basement (uncredited) |
 Harry WilsonMonster in Basement (uncredited) | Monster in Basement (uncredited) |