As the number of newly diagnosed cancer patients and the survival rates of cancer increase, more and more cancer patients are facing distressing physical and psychosocial problems as a result of their cancer and its treatment. To address these problems, a 12-week rehabilitation group program for cancer patients (all cancer types), combining physical exercise and psycho-education, was tested in a longitudinal cohort study (n=658). At baseline, participants reported a low quality of life, measured by the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) (range 0-100). Halfway through the intervention significant improvements were found in all domains, except cognitive functioning. At the end of rehabilitation, participants had reached significant improvements on all outcome variables: in global quality of life (from 63.0 to 71.9), emotional functioning (from 66.2 to 74.4), cognitive functioning (from 70.5 to 74.4) and fatigue level (reduction from 49.8 to 41.8) while, moreover, non-breast cancer patients showed clinically relevant improvement in physical functioning (from 67.3 to 80.4) and social functioning (from 63.4 to 79.4) and non-working patients showed a clinically relevant improvement in role functioning (from 57.0 to 69.6).