"Blood on Satan's Claw is cinematic diabolism of some style and intelligence...a horror movie of more than routine interest."
- Vincent Canby, The New York Times

"For a pleasant variation on the usual unsubtle, corny examples of the current British horror genre, this is one for the collectors."
- Films and Filming

"...offers a satisfying sense of sunlight-and-terror."
- Judith Crist

"An effective, serious witchcraft thriller..."
- Michael Weldon, The Psychotronic Encyclopedia of Film

"...Haggard's picture collapses into gory but well-shot sensationalism...Hayden gives a stronger performance than in Taste the Blood of Dracula [1970], but neither her presence nor that of Wymark, who played Cromwell in Reeves' film [The Conqueror Worm, 1968], are sufficient to counteract the picture's exploitative approach, even though the director manages to cloak this under excellently stylized imagery."
- The Encyclopedia of Horror Films

"When 1971 is behind us, I hope I may be able to point to this neat little witchcraft thriller as one of the "sleeper" highlights of the year. I could hardly have expected a film as literate as this from the prolific but undistinguished Tony Tenser...The opening scenes are Lovecraftian in structure....The fact that we never really understand the creation, nature or form of the demon, his intent or the circumstances by which he controls his disciples, is at once a flaw and strength of the film...Ignore the title and programmer status. It deserves to be seen."
- John Duvoli, Cinefantastique

"Blood on Satan's Claw was not typical of the British horror films of the late sixties and early seventies...Quite apart from the plot having no distinct hero figure, it was further complicated by an exceedingly erratic narrative thread and an oppressive atmosphere of madness and decay. It also intertwined two of the cinema's greatest taboo subjects: the inherent evil of children and the overt sexuality of evil. Moody, downbeat, thoughtful and, at times, both lyrical and overtly sadistic, Blood on Satan's Claw joined that small cartel of contemporaneous British horror films – including Witchfinder General...which occupy their own, very precise space at the outskirts of the genre."
- David Taylor, Shock: The Essential Guide to Exploitation Cinema

"...a concerted effort to recapture the glories of Witchfinder General...it had a downbeat feel that was depressing without having the reasoned misanthropy of the Reeves film...but the direction and cutting gives the film an unsettling, disorienting feel...The finale is frightening not because of the cheesy monster, but because Wymark makes you believe that, although he must kill the creature, he is absolutely terrified of it. Photographer Dick Bush films the story in glorious autumnal colours, and this lushness contrasts nicely with the darkness of the tale."
- Andy Boot, Fragments of Fear: An Illustrated History of British Horror Films

"Richly atmospheric horror film with erotic overtones, somewhat gruesome at times."
- Leonard Maltin's Movie Guide

"Moderately frightening, rather silly but at least original period horror comic."
- Halliwell's Film & Video Guide

"....for the first hour Piers Haggard keeps his theme and the blood flowing nicely...Sadly, Haggard lets things slip, and the make up man takes over."
- Adrian Turner, TimeOut Film Guide

"Gruesome British supernatural chiller (tensely directed by Piers Haggard from Robert Wynne-Simmons' script)...Period atmosphere and costuming are excellent."
- John Stanley, Creature Features

"Atmospheric British horror...This mood piece...is almost in the category of The Conqueror Worm, thanks to strong performances hard-edged violence, and convincing period detail."
- James O'Neill, Terror on Tape

"...a taut, eerie and exciting period gothic that contains some genuine chills amidst the commercially exploitable sex and gore. Intended as a successor, in spirit if not in story, to Witchfinder General, the film is an unexpectedly intelligent study of devilry and repression...What immediately strikes you when watching Blood On Satan's Claw is how well it uses the usually tranquil English countryside as a place of terror. This wasn't something new in 1970 – Tigon's earlier Witchfinder General is still one of the great examples of this usage thanks to John Coquillon's work as DP – but it's worth mentioning Dick Bush's extraordinarily evocative photography of a rural community."
- Mike Sutton, DVD Times

"...the best film TIGON made was Blood on Satan's Claw. Taking the theme of possession and taking supernatural evil seriously, Satan's Claw has a compromised script and an undistinguished cast. Yet it works brilliantly....the style of the film is simultaneously creepy and thoughtful. It doesn't apologize for itself or compensate for scaring you with cheap gags, irony or physical humour. Satan's Claw just does its job and does it better than most. With more resources and more time to script edit, this would have been a masterpiece."
- John White, 10bullets.com

"...Satan's Claw is a nasty film. A very, very nasty film, with rape, child abduction, limb-lopping, DIY surgery, insanity and murder piled higher and higher until it's hard for the viewer to take much more. Which, let's face it, is pretty much everything a horror film should be."
- British Horror Films, www.britishhorrorfilms.co.uk