The Psychoeducational Profile-3's (PEP-3) ability to estimate cognitive and language skills of 136 children (20-75 months) with autism spectrum disorders (ASDs) across a range of functioning, and the association between the PEP-3 and ASD symptomatology was examined using retrospective data. PEP-3 cognitive and language measures were positively correlated with similar measures on the Child Development Inventory, the Merrill-Palmer Revised, and the Vineland Adaptive Behaviour Scale-2. The PEP-3 sometimes provided higher or lower estimates than other measures. Significant differences were found between diagnostic groups on PEP-3 cognitive and language measures. PEP-3 cognitive scores correlated positively with scores on the Autism Diagnostic Observation Schedule. Findings support the use of the PEP-3 to measure cognition and language in children with ASDs.