Objective We developed an integrative day care clinic program for cancer patients focusing on mind‐body techniques and health‐promoting lifestyle modification (7‐hour once‐per‐week group sessions over 12 weeks). Methods A cohort study design with a waiting group was implemented. Outcome parameters were assessed at the beginning, at the end of the active program, and at a 6‐month follow‐up. Patients waiting >4 and <12 weeks before treatment start were allocated to the waiting group and additionally assessed at the start of their day care program. Outcome measures included quality of life (FACT‐G, FACT‐B/C, WHO‐5), fatigue (FACIT‐F), depression/anxiety (HADS), and mood states (ASTS). A per protocol analysis using mixed linear models was performed. Results One hundred patients were screened on‐site for eligibility. Eighty‐six cancer survivors (83% female; mean age 53.7 ± 9.7 years; 49% breast cancer) were included into the study. Sixty‐two patients were allocated to the intervention group and 24 patients, to the waiting group (mean waiting time 5 ± 1 weeks). Sixty‐six data sets were included in the final analysis. Significant improvements were observed in favor of the intervention group after 12 weeks compared with the waiting group at the end of the waiting period for quality of life, anxiety/depression, and fatigue. Results from the 6‐month follow‐up for the whole study population showed lasting improvement of quality of life. Conclusions The program can be considered as an effective means to improve quality of life, fatigue, and mental health of cancer patients. Moreover, it appears to have a sustainable effect, which has to be proved in randomized trials.