Because of progress in cancer treatment, the development of cancer is not necessarily a death sentence. On the other hand, approximately half of patients actually die from cancer even today, and many cancer patients require care for psychological distress. From the viewpoint of psychiatric diagnosis, the most common psychiatric conditions experienced by cancer patients are adjustment disorders and/or major depression. From the viewpoint of psychological status, however, cancer patients without psychiatric disorders may still suffer from fears of recurrence during the survival period and psycho-existential distress or death denial during the terminally ill phase. Concerning psychological symptoms related to cancer treatment,anticipatory nausea and vomiting is a well-documented condition among patients receiving high doses of emetogenic chemotherapeutic agents. Thus, most cancer patients experience some form of psychiatric disorder and/or psychological distress and should receive appropriate management and care during the course of their illness. Mental health professionals are expected to play a role in managing patients’distress. In general,because cancer patients are more likely to prefer psychotherapeutic intervention to pharmacological therapy for the management of their distress, mental health professionals must rely on psychotherapeutic approaches. Thus, mental health professionals need to provide care for cancer patients based on an understanding of the course of disease. This review focuses on the psychological distress experienced by cancer patients and provides an overview of essential psychological care, focusing on psychological interventions for ameliorating the psychological distress of cancer patients. Furthermore,the novel system of registered psycho-oncologists established by the Japan Psycho-oncology Society to foster psycho-oncology professionals who can provide appropriate specialized care to cancer patients and/or their families is also introduced.