Impairments in nonverbal communication are a defining feature of autism spectrum disorder (ASD) and can manifest as difficulty with, or even complete lack of, communication of emotional states via production of facial affect or vocal affect. The purpose of this study was to evaluate psychometric properties of a novel multimodal dialog based Affect Production Task (APT) in children and adolescents (ages 8-17) with a diagnosis of autism (N=72) or neurotypical controls (N=37). Participants completed activities designed to quantify objective facial and vocal affect production ability using audiovisual capture. Criterion, ecological, and discriminant validity were assessed. Psychometric performance across task conditions, age, sex, and race-ethnicity also was examined. Results of this initial psychometric evaluation suggest that the APT is a valid measure of affect production abilities in children and adolescents, and that psychometric performance is invariant to age, sex, or race/ethnicity.