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Levels of physical capability, an individual's ability to undertake the physical tasks of daily living, are assessed using performance-based and self-reported measures. By examining discordance between these measures, two groups can be identified; one reports poor capability yet performs to higher levels than expected (underestimators), whilst the other report higher levels of capability than expected given their poor performance (overestimators). It was hypothesised that discordant groups would have different characteristics. Data from the MRC National Survey of Health and Development were used to explore the concordance and discordance between self-reported and performance-based measures of physical capability at age 60-64. To identify two discordant groups, and distinguish these from a reference concordant group, summary scores of the selfreported and performance-based measures were produced and plotted against each other. The selection of measures used to produce the self-reported summary score was informed by analyses that explored the hierarchical order in which participants reported difficulty with the physical tasks of daily living. Multinomial logistic regression models were used to investigate the associations between discordance and factors selected a priori based on comprehensive literature reviews Sex, education, occupational class, smoking history, pain and chronic depression, were associated with discordance at age 60-64. For example, those with higher socioeconomic position, who experienced pain or chronic depression were more likely to underestimate their physical capability, whilst women and ex-smokers were less likely to overestimate their physical capability. Evidence of discordance suggests that there may be individuals in early old age who have unmet needs relating to their physical capability when assessment is based on either self-reported or performance based measures alone. Future policy should ensure these individuals are identified; factors associated with discordance can be used to identify target groups who may benefit from intervention that prevent or minimise age-related declines in physical capability.