Rationale, aims and objectives Support workers are the largest single group of staff involved in the delivery of health and social care in the UK; however, their roles are heterogeneous and are influenced by several contextual factors. The aim of this study was to elucidate the contribution of the elements and context of work undertaken by support workers in health and social care. Methods Thematic review of the literature 2005/2006, updated in 2008. Results A total of 134 papers were included in the review, from which we identified four domains of work and four core roles of support workers. The four domains of support worker work are direct care, indirect care, administration and facilitation. The four 'core' attributes of support worker roles were being a helper/enabler, a companion, a facilitator and a monitor. The more 'technical' components of support worker roles are then shaped by contextual factors such as staffing levels and the delegation processes. Conclusion Despite the heterogeneity of support worker roles, there are some uniting 'generic' features, which may form some or all of the role of these practitioners. Contextual factors influence the specific technical aspects of the support role, accounting in part for their heterogeneous role.