Psycho-oncology has two purposes corresponding to the psychosocial aspects of cancer: 1. to clarify the psychosocial impacts of cancer on the quality of life of the patient, family and staff; 2. to clarify the role that psychosocial and behavioral variables may have in cancer risk and survival. For these purposes, patient education, counseling, behavioral and psychopharmacological techniques have been applied to clinical oncology. In this paper, we review psycho-oncology and its scientific background, with respect to neuroradiology and molecular genetics, as well as psychiatry, psychology, epidemiology, pharmacology and immunology.