Family carers of people who have long term illness often experience physical and mental health morbidities, and burden. While there is good evidence to suggest that carers benefit from psychosocial interventions, these have primarily been delivered via face-to-face individual or group-formats. eHealth interventions offer a novel, accessible and self-paced approach to care delivery. Whether these are effective for carers' wellbeing has been little explored. This paper reports the first comprehensive systematic review in this area.