Tehran University of Medical Sciences Basic & Clinical Cancer Research 2228-6527 11 4 2020 05 15 182 187 Nahid Ghanbari Department of Psychology, Ardabil Branch, Islamic Azad University, Ardabil, Iran. Mohammad Narimani Department of Psychology, Faculty of Education and Psychology, University of Mohaghegh Ardabili, Ardabil, Iran. 2020 01 20 2020 05 15 Background: Preoperative psychological distress, including anxiety, stress, and depression, is an important issue in psychological pathology. It is of double importance among vulnerable groups such as patients with incurable chronic diseases (such as breast cancer) and simple diseases (such as cholecystitis). We assessed the development of anxiety and stress symptoms in two groups undergoing surgery; breast cancer patients and patients undergoing cholecystectomy. Methods: In a causal-comparative study, 30 participants were selected consecutively from a list of candidates for mastectomy and were compared with 30 patients undergoing cholecystectomy in terms of psychological distress. All samples completed the Depression, Anxiety, and Stress Scales-21 (DASS-21). Results: Our results showed that the average scores of stress (P < .000F=1/71), anxiety (P< .000F=117/556), and depression (P < .000F=3/41) were higher in patients with breast cancer surgery (mastectomy) than in those undergoing cholecystectomy surgery. Conclusions: Patients themselves have significant effects on the level of their stress. So, in this study, we attempted to examine the effects of stress and anxiety on people before surgery. https://bccr.tums.ac.ir/index.php/bccrj/article/view/332