It has been suggested that home sharers, particularly spouses, act as substitutes for formal health and social care provision. This hypothesis was investigated in relation to three independent samples of elderly people, using comparable methodology in London (urban area) and Essex (semi-rural area). The uniqueness of the study lies in the ability to make comparisons between younger and older elderly people, in particular with those aged 85 and over. Utilisation of health and social services was found to be higher in the urban area, and it increased with age. Marital status was not associated with service use nor with contact with general practitioners in any age group or area. The social network variables analysed had little or no predictive ability in relation to recency of contact with general practitioners (GPs). Household size was associated with total use of health and social services, and social services in particular. The multivariate analysis confirmed that household size was a strong predictor of use of home help and meals on wheels services; functional status was the best predictor of use of district nursing services.