We conducted a systematic review of the effectiveness of networked ICT interventions in supporting carers of people with dementia. Five bibliographic databases were searched and a total of 1456 abstracts were identified as potentially relevant. From these we identified 15 papers describing five interventions: ComputerLink, AlzOnline, Caring for Others and two studies from the REACH project (TLC and CTIS). The interventions reviewed were multifaceted with elements of networked peer support. Outcomes were inconsistent but suggested that the interventions had moderate effects on improving carer stress and depression. Treatment effects were found to vary with caregiver characteristics such as ethnic groups, formal support and baseline burden. Further evaluation is needed in robust trials with good follow-up.