Predictors of breast cancer worry in healthy women remain unclear. Healthy women less than 50 years (N = 857) completed measures of family history, anxiety, absolute and comparative risk perceptions, illness perceptions, and breast cancer worry. Regression analyses revealed that having a family history of breast cancer, greater anxiety, higher absolute risk perceptions and negative illness perceptions predicted 45 per cent of the variance in breast cancer worry. Risk perceptions also partially mediated the relationship between illness perceptions and worry. This study provides novel evidence that both illness and risk perceptions are predictors of breast cancer worry in younger women from the community.