In this investigation, the socio-communicative skills of 29 children with Williams syndrome aged 2 (1/2) to 5 (1/2) years were examined using the Autism Diagnostic Observation Schedule (ADOS) Module 1. Most of the participants showed socio-communicative difficulties. Approximately half of the participants were classified by the ADOS algorithm as "autism spectrum." Three participants were classified "autism." Difficulties with pointing, gestures, giving, showing, and eye contact were present for more than half of the participants, with many also showing difficulties with initiation and response to joint attention and with integration of gaze with other behaviors. Expressive and receptive language abilities of the children with Williams syndrome classified "autism spectrum" were weaker than for children classified nonspectrum, but expressive and receptive language level did not account for the socio-communicative difficulties. Implications for our understanding of the socio-communicative abilities of young children with Williams syndrome and diagnostic practices regarding dual diagnosis are discussed.