There is considerable interest among organisations such as primary care trusts and health action zones in commissioning welfare benefits advice services in primary healthcare settings as part of local strategies to reduce health inequalities. However, very little is known about the contribution to health of such services or about the health status of those who use them. The present study reports on a longitudinal study of the contribution to individual health of welfare benefits advice in primary care that has gathered baseline demographic and health data on 345 research subjects. The average age of the subjects was 54 years, and they were likely to be unemployed or retired. Over 85% were advised to apply for welfare benefits or to appeal against the loss of a benefit, the most common benefit being Disability Living Allowance (over 50% of all subjects). Three-quarters reported a physical disability or long-term illness that limited their daily activity, and over half reported arthritis or rheumatism. Scores on the short form 36 (SF-36) which quantify self-reported physical and psychosocial aspects of health, were much lower than population norms, indicating poorer health. The burden of illness borne by users of these services is not surprising. However, reliable data has not previously been available. It appears that primary care provides good access to advice services for people in middle and old age, but not to other groups (e.g. families with young children, substance misusers or those with mental health problems). Better data collection by advice services, wherever located, would strengthen their understanding of the needs of those whom they serve, and help them to identify under-served groups. These data could be used to support requests for continued or extended funding.