There has been much speculation about whether social support plays a role in maintaining good health in the elderly, but few investigations to determine whether an intervention to increase social support can have subsequent effects on health, particularly on mental health. This Note evaluates whether a community-based in-home preventive program can change the level of social support and improve health status in an older population. The author randomly assigned noninstitutionalized Santa Monica, California, residents aged 75 and over, who were recruited from a voter registry, to intervention (n=216) and control (n=198) groups. Intervention group participants were visited in their homes by a gerontological nurse practitioner (GNP) every three months for one year. The GNP performed a multidimensional evaluation, and in collaboration with geriatricians, recommended preventive actions. Outcome data were collected by independent examiners for experimental and control subjects every four months. At baseline, there was a significant positive association between social support and health status, and an even stronger negative association between social support and depression. Specifically, tangible support (e.g., transportation) appears to be the most influential component of social support in those aged 75 and over. However, the intervention group participants did not have significantly different levels of social support after the first year.