Psychological symptoms, particularly postpartum depression, may impair women’s well-being after childbirth. Mind–body treatments such as hypnosis are available to help prepare women to maintain or improve their well-being postpartum. The aims of the present study are to determine the effectiveness of a hypnosis intervention in alleviating psychological symptoms (stress, anxiety, and depression) and the symptoms of postpartum depression. A quasi-experimental design was utilized in this study. The experimental group participants (n = 28) received a hypnosis intervention at weeks 16, 20, 28, and 36 of their pregnancies. Participants in the control group (n = 28) received routine prenatal care. The final data collection, occurring at two months postpartum, included 16 women from the experimental group and 11 women from the control group. The Depression Anxiety Stress Scale–21 (DASS-21) was used to measure psychological symptoms, and postpartum depression was assessed using the Edinburgh Postnatal Depression Scale (EPDS). The results at two months postpartum showed that the experimental group had significantly lower postpartum anxiety than the control group (M = 2.88 versus M = 38.36, p = .023). Similarly, the experimental group had significantly lower postpartum depressive symptoms than the control group (M = 1.25 versus M = 6.73, p < .002). Group differences in postpartum stress symptoms were not significant (p = .363). Finally, the results indicated that the experimental group experienced reduced postpartum depression when compared to the control group (M = 5.69 versus M = 10.64, p < .001). Thus, hypnosis conducted during pregnancy may promote improvements in psychological well-being postpartum.