This study examines factors associated with caregiver burden in 82 HIV-positive (HIV+) and 162 HIV-negative (HIV-) partners of men with AIDS. We expected HIV+ caregivers to report more burden than HIV- caregivers because of the toll of their disease on their resources. HIV+ caregivers did report more burden and, compared with the HIV- caregivers, they were more religious or spiritual, had less income, and coped by using more positive reappraisal and cognitive escape-avoidance and by seeking social support. Comparisons of HIV+ caregivers with 61 HIV+ partners of healthy men indicated that most differences between HIV+ and HIV- caregivers were associated with HIV seropositivity rather than caregiving. However, of the variables associated with HIV seropositivity, only religiosity or spirituality contributed independently to burden in HIV+ caregivers, suggesting a relatively weak link between HIV seropositivity and caregiver burden. The model explained 62% of the variance in burden in HIV+ caregivers and 36% of the variance in HIV- caregivers.