Peer support groups may be important in long-term rehabilitation after a cardiac event. Questions can be raised about the clients that peer support groups attract. The aim of this study was to compare people who chose to attend peer support groups after a cardiac event with people who declined to attend with regard to health conditions, personal traits, lifestyle and available social support. Patients who sustained a myocardial infarction or were treated with percutaneous transluminal coronary angioplasty or coronary artery bypass surgery (n = 197) responded to a questionnaire. The results showed that there were differences between attenders (n = 64) and non-attenders (n = 133). Attenders reported more health problems than non-attenders, but scored higher on several dimensions of social support. Non-attenders, however, seemed to have a somewhat more relaxed attitude to life than attenders. The homogeneity of the subjects made it difficult to discern which personal and situational factors were of importance for social support seeking in peer support groups. The research indicates that innovative approaches are needed to encourage participation in existing peer support groups.