OBJECTIVE: To assess the social and economic impact of HIV-related illness and death on the spouses of HIV-infected individuals. METHODS: From population-based surveys in the 1980s in Karonga district, northern Malawi, 197 'index individuals' were identified as HIV-positive. A total of 396 HIV-negative 'index individuals' were selected as a comparison group. These individuals, and their spouses and children, were followed up in 1998-2000, in a retrospective cohort study. All analyses compared spouses of HIV-positive indexes with those of HIV-negative indexes. RESULTS: By 1998-2000, most marriages involving an HIV-positive index individual had ended in widowhood. Twenty-Six percent of the wives of HIV-positive index men experienced household dissolution precipitated by widowhood, compared with 5% of the wives of HIV-negative index men. Corresponding percentages for husbands of index women were 14% and 1%. Widow inheritance was uncommon. The remarriage rate among separated or widowed wives of HIV-positive index men was half that of such wives of HIV-negative index men. About 30% of surviving wives of HIV-positive index men were household heads at the time of follow-up, compared with 5% of such wives of HIV-negative index men. Almost all these women were widows who lost their husband when >35 years old, and they had relatively few household assets. CONCLUSIONS: The social and economic impact of HIV on the spouses of HIV-infected individuals in rural northern Malawi is substantial. Interventions that strengthen society's ability to absorb and support widows and widowers, and their dependents, without necessarily involving the traditional coping mechanism of remarriage, are essential.