Background: Patients with cancer receiving oncological treatment often suffer from a reduced quality of life (QoL) and resilience. Objectives: The aim of this study was to evaluate the effect of an interdisciplinary integrative oncology group-based program on resilience and quality of life in patients with cancer during or after conventional oncological therapy. Methods: This prospective longitudinal single-center study evaluated the resilience (Resilience Scale), quality of life (EORTC-QLQ C30), anxiety, depression (Hospital Anxiety and Depression Scale), and distress levels (Distress Thermometer) of 60 patients with cancer who participated in a 10-week interdisciplinary integrative oncology group-based program during or after cancer treatment in outpatient clinics. An average of 12 (range 11-13) patients participated in each 10-week group. The program included recommendations for diet, stress management, relaxation, and exercise, as well as naturopathic self-help strategies and psychosocial support. Results: There were slight increases in global quality of life scores (week 0: 58.05 ± 20.05 vs week 10: 63.13 ± 18.51, n = 59, P = .063, d = −.25) and resilience scores (week 0: 63.50 ± 13.14 vs week 10: 66.15 ± 10.17, n = 52, P = .222, d = −.17) after the group program compared to before; however, these changes were not statistically significant and had small effect sizes. Patients with at least moderate anxiety symptoms ( P = .022, d = .42) and low resilience ( P = .006, d = −.54) benefited most from the program. The patients reported no relevant side effects or adverse events from the program. Conclusions: No significant effects on global quality of life or resilience were found in the general sample; notably, patients with anxiety and low initial resilience benefited the most from the program.