OBJECTIVES: To examine the association of chronic degenerative diseases with locomotor activity limitation and social participation among older British women. METHODS: Cross-sectional survey of 4,286 women aged 60-79 years from 23 towns in England, Scotland and Wales. RESULTS: The prevalence of locomotor activity limitation was 37.2% and 33.5% of women had difficulty with some aspect of social participation. This prevalence of locomotor activity limitation and difficulties with social participation increased with increasing age and with increasing number of chronic diseases. All chronic diseases assessed were independently (of each other and confounding factors) associated with locomotor activity limitation. Associations were particularly strong for stroke (OR 5.44, 95% CI 3.38-8.75), arthritis (OR 3.95, 95% CI 3.25-4.81) and coronary heart disease (OR 2.26, 95% CI 1.77-2.88). The population attributable fraction for locomotor activity limitation was greatest for arthritis: 37.8% (95% CI 32.0-43.1) and coronary heart disease: 6.7% (95% CI 4.8-8.8). Locomotor activity limitation was strongly associated with social participation. Most chronic diseases of ageing were independently (of locomotor activity limitation, other chronic diseases and confounding factors) associated with reduced social participation. CONCLUSIONS: Locomotor activity limitation and difficulties in social participation are common. Arthritis and coronary heart disease contribute importantly to locomotor activity limitation and difficulties with social participation. Effective strategies to prevent or limit the disabling impact of these conditions are essential to improving the quality of life of older women.