HIV/AIDS has added an unparalleled number of children to South Africa's orphan population. The theory of planned behavior (TPB) was used to investigate the decision-making processes of potential substitute caregivers of children orphaned by AIDS. Existing foster and adoptive parents (n = 175) completed a self-report postal survey. Of the sample, 76.0% reported willingness to care for an HIV-negative child and 62.2% an HIV-positive child. Analyses of the theory's components reveal contradictory and disappointing results. While the theory is most useful in conceptualizing the factors that bear on fostering and adoption, the current study suggests that the TPB is limited in its ability to address the complexity of decisions that attend fostering and adoption of children orphaned by HIV/AIDS.