We examined anxiety and depression clinical symptom levels in 42 typically-developing (TD) siblings of children with high-functioning autism spectrum disorder (HFASD), compared to 42 TD siblings of TD children, matched on age, ethnicity, and gender. Participants were between the ages of 6 and 16. Groups were compared using the parent-report and child self-report versions of the Behavior Assessment System for Children, Second Edition, anxiety and depression clinical scales. Within-group differences were examined for parent versus child ratings. Multivariate procedures did not support clinically elevated levels of internalizing problems in siblings of children with HFASD. Results from both sources were consistent with the overall finding. The findings do not support an increased need for targeted intervention, though clinical and school-based practitioners should attend to clinical warning signs if presented.