Based on the stress buffering hypothesis, this study considered the moderating effect of perceived social support from adults other than the mother living with HIV (MLH) on the attachment-child anxiety relationship. The study utilized baseline data from the Teaching, Raising, and Communicating with Kids study, a randomized controlled trial testing the efficacy of an HIV disclosure intervention. Overall, results of this study demonstrated a significant negative association between MLH-child attachment and anxiety when controlling for child age and gender. However, results found no significant interaction effect between attachment and general perceived social support on anxiety, with informational social support in fact strengthening the negative association of attachment on anxiety. These findings underscore the consideration of children’s relationships with family members and other adults as a target for addressing anxiety symptoms in youth affected by maternal HIV, as well as the need to develop measures to accurately capture the child’s relationship context.