Marriage and partnerships bring about non-negligible health risks in populations with generalized HIV epidemics, and concerns about the possible transmission of HIV thus often factor in the decision-making about partnership formation and dissolution. The awareness of and responses to HIV risk stemming from regular sexual partners have been well documented in African populations, but few studies have estimated the effects of observed HIV status on marriage decisions and outcomes. We study marriage dissolution and remarriage using longitudinal data with repeated HIV and marital status measurements from rural Malawi. Results indicate that HIV positive individuals face greater risks of union dissolution (both via widowhood and divorce) and lower remarriage rates. Modeling studies suggest that the exclusion of HIV positives from the marriage or partnerships market will decelerate the propagation of HIV.