Psycho-oncology addresses the psychosocial care of patients with cancer. Systematic research on the interactions between biological, psychological and social factors before, during and after cancer has only been carried out for a few decades. All cancer patients, their relatives and the treating medical team should receive low-threshold offers for psychosocial support. The demand for interdisciplinary counselling and therapy detected by clinical diagnosis and by systematic screening, is not satisfactorily covered and is continuously increasing. In collaboration between the involved professional groups, education and professional qualifications for psycho-oncologists are still being developed.