OBJECTIVE: an abbreviated form of the Duke Social Support Index (DSSI) as used in a large longitudinal study of older Australian women was examined with respect to factors that might be expected to affect social support for older women over time. METHODS: in this large cohort study two sub-scales of the DSSI, one describing the size and structure of the social network (four items) and the other perceiving satisfaction with social support (six items), were analysed in relation to outcome and exploratory variables. RESULTS: over a 3-year period, the network score increased among women whose life circumstances meant that they were likely to receive more support (e.g. recent widowhood). Likewise, those women at risk of becoming more socially isolated (e.g. those with sensory loss) became less satisfied with their social support. Changes in both measures were tempered by women's mental health and optimism. CONCLUSIONS: although the sub-scales of the DSSI may not fully reflect the complexity of social support paradigms, they are responsive to changes in the lives of older women and can be useful in community-based epidemiological studies.