Background/Aim: People who are undergoing cancer treatment often ask themselves what they can do in addition to conventional medical therapy with regard to nutrition, activity, and complementary methods. However, we know little about the motivation why people opt for one or the other measure. The aim of this study was therefore to examine the extent of physical activity (PA), healthy nutrition, and the use of complementary methods in relation to both demographic and psychological data. Materials and Methods: A questionnaire was used to collect data on demographic data, resilience, coherence, self-efficacy, spirituality, satisfaction, and complementary and alternative medicine (CAM) behavior, PA, and diet. Between March and July 2021, data from 446 patients were collected. Regression models and correlation analyzes were used to examine the associations between CAM use, diet and PA with the other variables surveyed. Results: CAM usage could only be predicted based on the patient's spirituality. Women used CAM more often and ate more healthily. Healthy eating was also related to younger age, shorter medical history, resilience, satisfaction, and coherence. In addition, the results showed that daily PA was related to the level of resilience, spirituality, and self-efficacy. Conclusion: Which people or why patients use CAM remains a question to be further investigated. Our data suggest that CAM seeks to address similar needs that others find in spirituality. In order to promote a healthy diet and PA in cancer patients in the future, various psychological variables seem conceivable. Resilience stands out, which is related to an overall healthier lifestyle.Many patients with cancer have a high interest in complementary and alternative medicine (CAM) (1, 2), diets (3, 4), physical and other activities, which allow them to get active and to contribute to the therapy (5). Aims are heterogenous ranging from fighting cancer, improving prognosis to increasing quality of life, and reducing side effects (6-8).While evidence on physical activity (PA) is level 1A (9, 10), and healthy nutrition is also recommended to all patients 106