The film has been described as a "box office disappointment," or a film which did "average business. In February 1960
Kinematograph Weekly wrote "I hardly expected the best people to rave about “ The Flesh And The Fiends "’ (Regal — Dyaliscope—British) and they didn’t. But no matter, the full-blooded melodrama concerning notorious body-snatchers Burke and Hare is, as was confidently anticipated by most astute bookers, scoring fluently at the Rialto, Coventry Street. It’s well to remember that horror films, unlike their TV counterparts, do not play to captive audiences. They ring the belli simply because a large section of the public likes spine-chilling fare."
The Monthly Film Bulletin wrote: "The attempt to do justice to the drama of medical ethics, centred on Dr. Knox and the celebrated horrors of Burke and Hare and with a torrid, time-consuming sub-plot about a prostitute thrown in, leads to continual changes of mood and interest that weaken the film's total effect. The more rhetorical medical school sections are inevitably overshadowed by the brisk gruesomeness of the many murder scenes, though there is little effort to build tension in these, and the studio sets fail to capture the grim atmosphere pervading many of Edinburgh's closes even today. Corpses toppling into brine baths, a rat hunt and a blinding provide most of the ghoulishness. Peter Cushing offers his usual polished performance, but the Oirish dialogue given to George Rose and Donald Pleasence makes them more comic than sinister."
Variety praised Cushing's performance as a "most effective study in single-minded integrity which knits the film together admirably."
The Radio Times Guide to Films gave the film 3/5 stars, writing: "This explicitly scary and darkly atmospheric retelling of the Burke and Hare story stars Peter Cushing, exceptional as the coldly ambitious Dr Knox ... The grimy poverty of 19th-century Edinburgh provides a vivid background to this unflinching shocker, which uses stark black-and-white imagery to startling effect." In
British Sound Films: The Studio Years 1928–1959 David Quinlan rated the film as "average", writing: "Busy, grisly shocker whose best asset is its period feel."
Film and Filming's Ian Moss criticized the film, writing "I can't understand anyone wishing to see this film voluntarily," and arguing that the script afforded the characters no depth. ==Versions==