Emotional and behavioral problems (EBPs), such as anxiety, overactivity, and aggression, can influence the diagnosis of autism spectrum disorder (ASD). The gold standard diagnostic tool for ASD, the "Autism Diagnostic Observation Schedule--Second Edition," includes three items ("E-codes") for EBPs that are frequently associated with ASD. Few empirical investigations have explored the use of E-codes. This study examined the relationship between E-codes and child characteristics (e.g., cognitive abilities, ASD symptom severity) in a sample of young children with ASD (N = 233). Findings indicated that E-codes positively correlated with ASD symptom severity and negatively associated with IQ. Symptom severity also significantly accounted for the variance in EBPs. Implications for ASD assessment as well as future research are discussed.