Early diagnosis of autism spectrum disorder (ASD) in children enables earlier access to services and better ability to predict subsequent development. A vast body of literature consistently shows discrepancies in the age of diagnosis between children from varying socio-economic levels, cultural and ethnic backgrounds. The present study examines the effect of sociodemographic factors on age of ASD diagnosis among the three primary ethnic sectors in Jerusalem region: secular and modern religious Jews, ultra-Orthodox Jews and Arabs. Findings indicate minimal differences in age of diagnosis prior to the age of six, although Arab children of this age were largely minimally verbal. After age six, no Arab children were referred for an evaluation.