The current study aimed to determine the effects of hypnotism on the severity of gastrointestinal symptoms and quality of life in individuals with irritable bowel syndrome (IBS). This trial study was conducted on 100 people with IBS in Shiraz, Iran. Hypnotism of participants was performed in 1-hour sessions for the intervention group at Weeks 4 and 6. A demographic characteristic questionnaire, Gastrointestinal Symptom Rating Scale, and IBS Quality of Life Index were used for data collection. The severity of gastrointestinal symptoms of participants in the intervention group significantly improved at 6 and 15 weeks after hypnotherapy. These individuals also had a significantly better quality of life after 15 weeks of hypnotherapy. Hypnotherapy may be beneficial in reducing gastrointestinal symptoms and improving quality of life in individuals with IBS. Combining this method with medicinal treatments could be effective for patients and health systems. [Journal of Psychosocial Nursing and Mental Health Services, 60(5), 55-62.].