Research has linked pre- and perinatal complications (PPCs) with increased risk for autism spectrum disorder (ASD). However, PPCs are also known risk factors for other mental health disorders. This study explored which PPCs are specific risk factors for ASD, as opposed to other forms of psychopathology, among a large sample of clinically-referred youth. Archival data were used from 1177 youth who were evaluated at a hospital-based autism clinic. Results from logistic regressions indicated that use of tobacco, alcohol, or drugs, or experiencing amniocentesis predicted inclusion in the non-ASD group, while physical difficulties with delivery predicted inclusion in the ASD group. Possible explanations and implications for these findings are discussed.