This study assessed the reliability and criterion-related validity of teacher ratings on the Adapted Skillstreaming Checklist for a sample of 133 children, aged 6-11 years, with autism spectrum disorder (without intellectual disability). Internal consistency for the total sample was 0.93. For a subsample, test-retest reliability was very good (r = 0.74; intraclass correlation coefficient = 0.85) at a 9-month interval. Child age, intelligence quotient, language abilities, and sex were not associated with the Adapted Skillstreaming Checklist total score. The Adapted Skillstreaming Checklist total score was inversely and strongly related to teacher ratings of autism spectrum disorder symptom severity. Significant positive correlations (moderate-to-high) were found between the Adapted Skillstreaming Checklist and prosocial skills scales and significant negative correlations (low-to-moderate) with problem behavior scales on a broad measure of child functioning. Implications and suggestions for future study are discussed.