Background Preoperative hypnosis has shown promising effects in controlling side effects from breast cancer surgery, but the feasibility and effects are largely unknown outside the US. Methods A mixed-methods approach was applied involving a large-scale population survey and a small-scale pilot study. The survey assessed attitudes toward hypnosis in a representative sample from the general population (n = 1049), while the pilot study involved interviews with 5 women who received hypnosis prior to mastectomy/lumpectomy. Results In the survey, 8% reported to have previous experience with hypnosis, and 67% reported willingness to accept hypnosis in a medical setting. Increasing age was associated with more skepticism, while previous experience was associated with less skepticism. In the pilot study, 4 themes were identified: (1) caretaking, (2) experiences related to hypnosis, (3) thoughts and feelings related to diagnosis, and (4) surgery. All participants reported positive experiences related to hypnosis, and none described unpleasant side effects or postoperative pain (pain intensity > 3) after surgery. Conclusions The results indicate that the general public is positive toward clinical hypnosis as a supplement to medical treatment and that preoperative hypnosis is feasible in Norwegian breast cancer patients. Trial Registration ClinicalTrials.gov Identifier: NCT04300283.