Medical decisional capacity (DC) refers to the ability to understand, appreciate, and make meaningful decisions about one's health. This is an important construct for children living with HIV whose involvement in their medical care has important implications for disease management. In this study, we assessed the relationship among DC, developmental stage, intellectual ability, and social-emotional functioning of children with and without HIV infection (n_50). We hypothesized a positive correlation between variables, but did not expect to find a difference in DC between groups. Results provided partial support for our hypotheses. There was a positive relationship between developmental stage and understanding, which is but one dimension of DC. Children with HIV infection obtained significantly lower scores on measures of intellectual and adaptive functioning, but there was no significant difference in DC between groups. Findings suggest that children living with HIV have the capacity to meaningfully participate in their healthcare despite lower intellectual and adaptive functioning.