Fifty-six women with stage II breast cancer receiving adjuvant chemotherapy were recruited for a study evaluating and comparing coping patterns for differences in physical and psychological side effects during treatment with adjuvant chemotherapy. Cluster analyses were used to split women into confrontive, avoidant-confrontive, avoidant-resigned, and resigned coping clusters. Side-effect measurements were taken on the day of adjuvant chemotherapy infusion and 3 and 7 days later. Repeated measures ANCOVAs indicated that coping clusters predicted significant variance in physical, psychological, and total side effects when variance in covariates was held constant. Confrontive subjects reported significantly fewer psychological and physical symptoms than avoidant-confrontive and avoidant-resigned copers. Confrontive copers also reported fewer side effects than resigned copers, but this difference was not significant when differences in covariate distributions were controlled. Particularly robust differences were noted when confrontive copers were compared with avoidant-confrontive copers. Results suggest that a critical component in optimal coping may be a willingness to discuss and think about illness.