Subliminal self-help audiotapes to aid weight loss were evaluated to determine if their apparent effectiveness is due to a placebo effect. All subjects were female students or staff who were both overweight and believed in the possible effectiveness of subliminal audiotapes. Three different groups of subjects were tested: One group listened to subliminal audiotapes purchased directly from a manufacturer, the 2nd group listened to comparable placebo tapes, and the 3rd group did not listen to any tapes at all. Each subject in each group was weighed once each week for 5 weeks. All 3 groups of subjects lost weight, and the average amount of weight lost by each group was approximately equivalent. These results provide no evidence that regular use of subliminal audiotapes leads to a placebo effect. Rather, the results suggest that regular use of subliminal audiotapes may simply make subjects more conscious of their weight.