Awareness of and responses to HIV health risks stemming from relations between sexual partners have been well documented in sub-Saharan Africa, but few studies have estimated the effects of observed HIV status on marriage decisions and outcomes. We study marriage dissolution and remarriage in rural Malawi using longitudinal data with repeated HIV and marital status measurements. Results indicate that HIV-positive individuals face greater risks of union dissolution (via both widowhood and divorce) and lower remarriage rates. Modeling studies suggest that the exclusion of HIV-positive individuals from the marriage or partnership pools will reduce the spread of HIV.