The aim of the current study was to investigate posttraumatic growth in Irish breast cancer survivors and the effects of optimism, coping, marital status and children. A cross-sectional between groups design was used. A postal questionnaire consisting of demographic questions, the Life Orientation Test Revised, Posttraumatic Growth Inventory (PTGI) and Mental Adjustment to Cancer scale (MAC) was distributed to women who had been diagnosed with breast cancer (n=30) and women without a life threatening illness diagnosis (n=30), using a snowball-sampling method. The breast cancer survivors perceived significantly higher growth than the comparison group. Optimism, Fighting Spirit and children were significantly positively related to growth in certain areas. The study recommends further research on post-traumatic growth in Irish males and on the effect of family structure.