The present project aimed to identify research activity at the health and social care interface in primary care within one National Health Service region, and to determine levels of research capacity and support within social services. The study was commissioned by a primary care research network (PCRN) in order to assess opportunities to increase research capacity within social services. Data were collected in two phases from 61 managers, team leaders and senior practitioners in social care, and six public health representatives in health authorities, using telephone interviews and focus groups. The findings highlighted a lack of infrastructure and support for research and development in social care. However, many social care respondents wanted opportunities to develop research skills with healthcare colleagues. Despite poor support, many small-scale projects were described, and many respondents showed an enthusiasm for engaging with research. Methods in use included surveys, action research, needs analysis and evaluation of service developments. Many examples of user involvement were given. Interface projects were usually instigated by interagency forums and funded from multiple sources. Most project work was motivated by service improvement or development, rather than aiming to produce generalisable knowledge. Barriers to conducting research included lack of confidence, research skills and time, as well as workload demands, lack of cover to release staff for research and lack of supervision. Research was not seen as legitimate work in some social care environments or as part of a career path. Existing joint working initiatives (such as the National Service Frameworks) were highlighted as flashpoints for potential research and evaluation activity. The findings suggest clear opportunities for PCRNs to develop research capacity at the interface with social care; for example, by signposting available resources, providing training grants and secondments for social care staff, and supporting interagency networks with a focus on evaluation. In turn, experience in promoting user involvement in social services could add value to research expertise at the primary care-social care interface.