To assess the validity of brief multidimensional measures of health, we studied 155 new residents of a long-term care institution. We collected self-reported measures of various aspects of health, as well as performance-based measures of physical and cognitive function. For six similar health dimensions measured using two self-reported methods, the average correlation between paired health dimensions was 0.64 (nonpaired correlation = 0.36). When we compared self-reports and performance on three closely paired health concepts, the average correlation of paired concepts was 0.49 (nonpaired correlation = 0.22). In a factor analysis, similar health dimensions measured using different methods tended to load on the same factor. Except for manual performance, performance-based and self-reported measures of physical and role function loaded on one factor. We conclude that brief measures of health and self-reported physical functioning in very old persons have acceptable validity.