Increasing attention is being given to treating the psychosocial as well as the physical needs of mastectomy patients. The present study investigated and endeavored to quantify the psychological, sexual, and social adjustment reactions to a mastectomy, the possible interaction of these reactions, and the role of environmental support in mediating these responses. Forty married and 37 unmarried mastectomy patients completed a battery of tests, including the Body-Cathexis/Self-Cathexis Scale, SCL-90, Derogatis Sexual Functioning Inventory, Social Adjustment Scale-Self-Report, Perceived Social Support Scale, and a Support Questionnaire. Overall findings indicated that a mastectomy has the potential for affecting psychological, sexual, and social adjustment for at least a limited time postoperatively. Specifically, significant correlations were found between psychological, sexual, and social adjustment. Significant differences were also demonstrated in the married/nonmarried comparison. Additionally, results emphasized the importance of environmental support for postoperative adjustment.