The aim of the investigation was to study psychological and psychosocial aspects of breast cancer. A literature search was done covering the period 1989-1992. The following research areas were studied: the relationship between psychological characteristics and breast cancer, and between psychosocial interventions and breast cancer; quality of life after breast cancer surgery and treatment; and the relationship between social support and breast cancer. The results showed that the medical community is divided into "believers" and "nonbelievers" with respect to whether or not psychosocial factors influence breast cancer outcomes. One of the best predictors of a women's postcancer adjustment is her psychological state before the breast cancer. The results also showed that the difference in psychological outcome between mastectomy and breast-conserving surgery was small and nonsignificant. Another finding was that the social context and social support from partner, family, friends, relatives and medical professions are important for survival. In conclusion, methodological problems were common in studying psychological and psychosocial aspects of breast cancer.