Background Few studies suggest the use of hypnosis in weight loss may be beneficial, especially when in conjunction with other lifestyle modifications or cognitive behavioral therapy. The primary aim of this study was to determine the ability of self-hypnosis audiotape to promote weight loss by measuring its effects on the Transtheoretical Model (TTM) of change stages and processes. Methods This study is a 3-week randomized double-blinded parallel controlled trial among adults who have overweight or obesity. The intervention group listened to a self-hypnosis audio file while the control group listened to a placebo audio file. Results Forty-six participants completed the 3-week follow-up visit. There was no association between progression across stages of change and self-hypnosis (X2(2, 46) = 1.909, p-value = 0.580). Gender, baseline BMD, and baseline S-weight had no effect on the association between stage change progression and self-hypnosis. The mean difference in weight at 3 weeks was −0.63 ± 0.43 kg in the hypnosis group and 0.0 ± 1.5 kg in the control group, independent t-test, p = 0.148. Conclusion Self-hypnosis was not associated with a progression in the TTM’s stages of change or with weight loss after 3 weeks. As this pilot study was underpowered, further research with larger sample size and an examination of the effect of various self-hypnosis content and duration is recommended.