This paper focuses on how online health forums may benefit the wellbeing of caregivers. An online questionnaire of caregivers assessed caregiver strain, forum use, and mental and physical wellbeing. Results show a positive relation between caregiver strain and using online health forums to seek emotional support. Furthermore, we find that caregivers with higher levels of caregiver strain report lower mental and physical wellbeing. This relation is however moderated by using online health forums. While the amount of time spent on the online forums did not moderate the relation between caregiver strain and wellbeing, the amount of activity (i. e. the number of messages posted per week) did: Active participation in online health forums attenuates the negative effect of caregiver strain on wellbeing.These findings suggest that online forums are valuable for caregivers and that it is active contribution that matters, rather than simply visiting the online health groups. © 2011 Walter de Gruyter GmbH & Co. KG.