Researchers have examined the progression of core symptoms in AD; however, the primary focus of lifespan research for children with ASD has been based on retrospective reports and the stability of diagnoses. The purpose of this study, then, was to conduct a cross sectional investigation of symptom expression of AD throughout the childhood years. Participants consisted of children ranging in age from 3 to 11 years old who were diagnosed with AD. The participants were partitioned into three age cohorts, with symptom endorsements of AD assessed through the Autism Spectrum Disorders-Diagnostic for Children (ASD-DC). Results indicated that symptoms of AD were no more pronounced at any one of the three age cohorts when compared to each other. Additionally, a non-significant linear trend was found, indicating that symptoms of AD in childhood remain stable and chronic. Implications of these findings and future directions for research in this area are discussed.