The New York Times concludes a mixed review with this: "for all its psycho-nonsense, this film has some mildly creepy spots and some occasional faint resemblance to "Rebecca," which it was obviously aimed to imitate." Slant Magazine gives it 2.5 out of 5 stars and concludes, "Insofar as every Fritz Lang film you haven’t seen is an undiscovered country, Secret Beyond the Door flies high over its seemingly anonymous place in the master’s 1940s phase."
Empire Online calls it a "Sloppy effort". Rotten Tomatoes has a critics score of 54%. TCM has information.