OBJECTIVE: To investigate the effect of adult death on household dissolution and migration. DESIGN: Demographic surveillance of the population in a rural area of northern KwaZulu Natal, South Africa. METHODS: Data on households resident in the surveillance area on 1 January 2000 were used to examine the effect of adult mortality and household risk factors on household dissolution and mobility between January 2000 and October 2002. Cox regression models were used to assess the risk of household dissolution and migration, controlling for multiple risk factors including causes of death, household composition and household assets. RESULTS: By October 2002, 238 households (2%) had dissolved and 874 (8%) migrated out of the area; 21% (2179) of all households had at least one adult death (18 years and older). Households where one or more adult members died during the follow-up period were four times more likely to dissolve, after controlling for household and community level risk factors [4.3; 95% confidence interval, (CI), 3.3-5.7]. The risk of dissolution was significantly higher in households with multiple deaths (2.3; 95% CI, 1.3-4.3). There were no significant differential risks associated with cause of death, age or sex of the deceased. Adult mortality in the household was not associated with migration. CONCLUSIONS: Poorer households, as measured by asset ownership, and households trying to cope with adult deaths are vulnerable to dissolution. The dramatic increase in adult mortality attributable to AIDS will increase the number of households that do not survive as a functional and cohesive social group.