STUDY OBJECTIVE: To identify which of seven indicators of socioeconomic status used singly or combined with one other would be most useful in studies of health inequalities in the older population. DESIGN: Secondary analysis of socioeconomic and health data in a two wave survey. SETTING: Great Britain. Participants were interviewed at home by a trained interviewer. PARTICIPANTS: Nationally representative sample of 3543 adults aged 55-69 interviewed in 1988/9, 2243 of whom were interviewed again in 1994. METHODS: Desirable features of socioeconomic measurement systems for identifying health inequalities in older populations were identified with reference to the literature. Logistic regression was used to examine variations in self reported health by seven indicators of socioeconomic status. The pair of indicators with the greatest explanatory power was identified. MAIN RESULTS: All indicators were significantly associated with differences in self reported health. The best pair of variables, according to criteria used, was educational qualification or social class paired with a deprivation indicator. DISCUSSION: For a range of reasons the measurement of socioeconomic status is particularly challenging in older age groups. Extending our knowledge of which indicators work well in analyses and are relatively easy to collect should help both further study of health inequalities in the older population and appropriate planning.