At one point, 'Stan' offers 'Bruno' a cigar. The name on the box is La Unica, a well-known Cuban-made brand at the time. The brand still exists, but the cigars are now made in the Dominican Republic with Dominican and Connecticut-grown tobacco leaves.
The movie, as released, is cut. There were gruesome scenes of the geek, bloodied, and insanely ripping apart the chickens. One could only hope that these scenes would be restored, since the editing destroyed the continuity.
According to Eddie Muller of the Film Noir Foundation, charlatans and grifters in the new age/mystic con would use the phrase "Are you a friend of Stan Carlisle?" or a variation on it to confirm that the person they were talking to was in the same line of business.
Studio head Darryl F. Zanuck found this movie so generally distasteful that he took it out of circulation; subsequent showings (either publicly or on television) were very rare. Its 2005 DVD release as part of the Twentieth Century Fox "noir" series brought "Nightmare Alley" back into wider circulation.
The telephone numbers of the Helen Walker character, Consulting Psychologist Lilith Ritter, are STAte 9862 (for her Office in the Lakeshore Building) and ROGrs Pk 8685 (for her Residence in the Belmont Apartments), both adjacent to the Lake Michigan waterfront on the near north side of Chicago.