Psycho-oncology is an interdisciplinary field encompassing physical, psychological, social, and behavioral aspects of the cancer experience for both patients and caregivers. The Japanese Psycho-Oncology Society and the Japanese Association of Supportive Care in Cancer developed evidence-based clinical practice guidelines for the care of psychologically distressed bereaved families who have lost members to physical illness including cancer. Because of the wide variation in international attitudes toward bereavement care, we have enhanced the descriptions in the general comment section. Two clinical questions were set and a systematic literature review was conducted by the guideline development group. The level of evidence and the strength of the recommendations were graded, and the modified Delphi method was used to validate the recommendation statements. Recommendations were as follows: nonpharmacologic interventions were indicated for severe psychological distress (depression and grief), and antidepressants were indicated for depression; however, psychotropic medications, including antidepressants, were not recommended for "complicated" grief. These guidelines facilitate the provision of appropriate care for distressed bereaved families and identify areas in need of further research.