A recent study documented the efficacy of the Early Start Denver Model (ESDM) delivered in a 1:1 fashion. In the current study we investigated the effectiveness and feasibility of the ESDM in the context of a long-day care community service, with a child-staff ratio of 1:3. Outcomes of 27 preschoolers with ASD undergoing 15-25 h per week of ESDM over 12 months were compared to those of 30 peers with ASD undergoing a different intervention program delivered in a similar community long-day care service. Children in both groups made gains in cognitive, adaptive and social skills. Participants in the ESDM group showed significantly higher gains in developmental rate and receptive language.