Vincent Canby of
The New York Times described the film as "gadget-happy American moviemaking at its most ponderously silly," and called Julie Christie "too sensible an actress to be able to look frightened under the circumstances of her imprisonment." In the
New York Daily News,
Rex Reed described
Demon Seed as the "kind of insane, self-indulgent, nauseating filmmaking . . . that almost destroyed the film industry in the sycophantic '60s. It isn't funny or original or shocking—it's just dumb and destructive and likely to drive potential audiences away at just the time when movies need them.
Demon Seed is pure trash, and the garbage cans are full enough already."
Variety wrote in a positive review, "All involved rate a well done for taking a story fraught with potential misstep and guiding it to a professionally rewarding level of accomplishment."
Gene Siskel of the
Chicago Tribune gave the film one-and-a-half stars out of four, writing that Julie Christie "has no business in junk like 'Demon Seed.'" Gary Arnold of
The Washington Post wrote that director Cammell "plays it dumb on a thematic level, ignoring the sci-fi sexual bondage satire staring him in the face ... What might have become an ingenious parable about the battle of the sexes ends up a dopey celebration of an obstetric abomination."
Kevin Thomas of the
Los Angeles Times called it a "fairly scary science-fiction horror film" that mixed familiar ingredients with "high style, intelligence and an enormous effort toward making Miss Christie's eventual bizarre plight completely credible," though he felt it "cries out for a saving touch of sophisticated wit to leaven its relentless earnestness." A critic for the
San Francisco Chronicle wrote that "this extraordinary science-fiction film appeals to both the imagination and the intelligence, although it is foolishly being sold as a horror film."
Perry Stewart of the
Fort Worth Star-Telegram wrote that "the film’s R rating seems warranted even though there’s no nudity or bad language. There’s a certain maturity to the subject matter. And Cammell’s indulgent camera soliloquies are hard enough for adult attention spans. Fidgety younger teens are apt to find it all a big yawn. As a matter of fact, I think I did, too." George McKinnon of
The Boston Globe said that "despite the title, there is nothing of the currently chic Satanic about this movie, but it is devilishly dumb."
Clyde Gilmour wrote in the
Toronto Star that "the rape and impregnation of Susan Harris by Proteus 4 may defy all logic and offend the pious, but it’s a smashing science-fiction spectacle, impossible to describe. The light-show that goes with it may well earn an
Oscar for the clever technicians involved. Less successful, because given less attention, are the human relationships in the story." Martin Malina, who reviewed the film alongside similar films
Rabid and
Audrey Rose in the same column of the
Montreal Star, wrote that the film "sounds more ridiculous than revolting". Scott Macrae of
The Vancouver Sun wrote that "the computer, which really runs this newspaper, failed last Friday night. All the stories in the system disappeared without so much as a puff of smoke. Reporters and editors were called in from their holiday weekend to repair the damage. None of us would have any trouble relating to the premise of a movie called
Demon Seed. Birds do it, bees do it . . . even computers need a little nookie . . . sorry, I'll try to handle this very intimate subject with taste and decorum." In the United Kingdom, Patrick Gibbs of
The Daily Telegraph said that the film was "so silly and so nasty" that he could not continue to describe its storyline. John Pym of
The Monthly Film Bulletin found the relationship between Susan and the computer to be "disappointingly undeveloped," and thought that the film would have been better if the computer had been more sympathetic in contrast to its creators. In Australia,
Romola Costantino of the
Sun-Herald said that "as you might expect, the computer's courtship is anything but erotic." Among more recent reviews,
Leo Goldsmith of
Not Coming to a Theater Near You said
Demon Seed was "A combination of
Kubrick's
2001: A Space Odyssey and
Polanski's ''
Rosemary's Baby'', with a dash of
Buster Keaton's
Electric House thrown in", and
Christopher Null of FilmCritic.com said "There's no way you can claim
Demon Seed is a classic, or even any good, really, but it's undeniably worth an hour and a half of your time." ==Release==