Background: As crisis caused by cancer results in imbalances and inconsistencies in body and mind as well as many psychological problems in patient's life, spiritual intelligence is a critical source to increase resistance to the disease. This study aimed to investigate the relationship between spiritual intelligence and psychological well-being in women with breast cancer in Babol. Methods: This descriptive-correlational study was conducted in the spring 2016 on 90 women with breast cancer referring for treatment to Shahid Rajaei hospital of Babolsar, and Ayatollah Rouhani and the counseling center for cancer registry of Babol. Demographic characteristics of patients such as age, marital status, education, occupation, place of residence (urban or rural), and duration of illness were recoded. In addition, two questionnaires of spiritual intelligence self-report inventory (SISRI-24) and Brief Reef Well-Being (18 questions) were used.