This paper examines the applicability of psychosocial group intervention for Japanese patients with primary breast cancer. The study included two phases. First, we examined the applicability for Japanese patients of an intervention model developed in a Western country. The model, based on the work of Fawzy and Fawzy (1994) on a structured psychosocial group intervention for cancer patients, is a series of six 1.5-h sessions that incorporate health education, coping-skills training, relaxation training and psychological support. Second, we formulated a Japanese version of the intervention model by modifying areas identified as inappropriate by participants in the first-phase study. We then evaluated this by conducting sessions of the modified model with 44 additional breast cancer patients. Of the ten participants in the first-phase pilot study, three (30%) dropped out and several inappropriate areas were reported. The areas requiring significant change were the provision of medical information and communication style with family members and doctors. No participants dropped out of the modified version, and very few found any program areas to be inappropriate. The findings suggests that psychosocial group intervention is applicable for Japanese breast cancer patients when the model accounts for cultural differences.