This briefing updates the research evidence on the effectiveness of day services featured in the publication ‘Day services for older people. Quality and effectiveness: a resource for providers and commissioners’ (2008). After outlining the range of services and activities covered by the term ‘day services’, the briefing summarises the key points and outlines the methodology used for the review. The review which involved literature searches on a number of databases, journal archives, websites in July and August 2011. These searches supplement the original literature search which was carried out in December 2007. The findings and summaries of research evidence are then presented, listing each report in turn. Due to the lack of evidence focusing on day services, research is also included on activities to reduce isolation and loneliness. The few studies that specifically evaluated the impact of day services found that older people and their carers benefitted from them. The review also identified the different types of day services that can address older people’s need for social contact, exercise, to engage in and make contributions to society.