Purpose. Despite increasing evidence of adverse effects on informal carers of caring for stroke survivors, little is known about the characteristics of carers and survivors that influence carer outcomes. The purpose of this review is to summarize factors influencing outcomes in carers of stroke survivors. Methods. A systematic review of studies identified from English language medicine, nursing and psychology databases from 1996 - 2006 was carried out. Results. Thirty-nine studies were identified. Studies from Europe and the USA investigating negative carer outcomes dominated. Carer psychological characteristics and survivor disability were shown to influence carer outcomes. However, the diversity of carers and outcomes investigated and differences in study timing post-stroke make generalizations difficult. Conclusions. Despite improvements in study design over the last two decades, atheoretical studies employing overlapping concepts and poorly defined participants still dominate. Future studies should have theoretical underpinning and should acknowledge the diversity of carers, survivors and their situations. In addition, future emphasis on positive carer outcomes may improve understanding of protective carer factors.