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." "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 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." 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.