The aim of this study was to evaluate the effectiveness of acceptance and commitment group therapy on quality of life and physical symptoms in gastro-intestinal cancer patients. The research was quasi-experimental with pretest, posttest and control group. The statistical population included 32 men with gastro-intestinal cancer. Subjects were selected by purposeful sampling and were randomly divided into two experimental (n = 16) and control groups. The experimental group received eight sessions of acceptance and commitment based group therapy and the control group was on the waiting list. Questionnaires used in this study were demographic information questionnaire, quality of life questionnaire for cancer patients and Powell and Enright physical symptoms questionnaire. The results showed that acceptance and commitment group therapy was able to improve the quality of life and physical symptoms.