Identifying effective, community-based specialized interventions for young children with autism spectrum disorder is an international clinical and research priority. We evaluated the effectiveness of the Early Start Denver Model intervention in a group of young children with autism spectrum disorder living in an Italian community compared to a group of Italian children who received treatment as usual. A total of 22 young children diagnosed with autism spectrum disorder received the Early Start Denver Model in a center-based context for 6 h per week over 6 months. The Early Start Denver Model group was compared to a group of 70 young children diagnosed with autism spectrum disorder who received treatment as usual for an average of 5.2 h over 6 months. Children in both groups improved in cognitive, adaptive, and social skills after 3 months and 6 months of treatment. Children in the Early Start Denver Model group made larger gains in cognitive and social skills after 3 and 6 months of treatment. The Early Start Denver Model group made larger gains in adaptive skills after 3 months of treatment. Our results are discussed in terms of implications for intervention research and clinical practice. Our study supports the positive impact of the Early Start Denver Model in a non-English-speaking community.