The current study aims to evaluate the psychometric properties of the Emotion Regulation and Social Skills Questionnaire (ERSSQ), a rating scale designed specifically to assess the social skills of young people with Autism Spectrum Disorder (ASD). The participants were 84 children and young adolescents with ASD, aged between 7.97 and 14.16 years with a mean IQ score of 90.21 (SD = 18.82). The results provide evidence for the concurrent and criterion validity of the ERSSQ Parent form, and the concurrent validity of the ERSSQ Teacher form. The clinical and theoretical implications are discussed, including the necessity of ratings across multiple contexts and the potential use of the ERSSQ in identifying individuals most in need of intervention and for planning and assessing the outcomes of social skills interventions.