BACKGROUND Previous studies have implicated emotional suppression, in particular suppression of anger, in the onset and progression of breast cancer. Many of these studies used non-standardized measures and failed to control for the effects of age and/or possible knowledge of diagnosis. The present study aimed to avoid these methodological errors in investigating the relationship of emotional suppression to a diagnosis of breast cancer in a large mammography screened population. METHOD Data were collected from 1151 women with suspicious mammograms recalled to a breast screening programme. Prior to multidisciplinary assessment women were asked to complete the Courtauld Emotional Control Scale. Imaging assessment outcome data and biopsy results were collected. RESULTS Fifteen per cent of this population subsequently were diagnosed with breast cancer. There were no significant associations between a cancer outcome and emotional suppression before or after the highly significant effect of age was taken into account. CONCLUSIONS These results suggest that suppression of emotion may not be relevant to the development of breast cancer. Its role in the progression of existing disease requires clarification.