This single subject design study examined two models of intervention: Denver Model (which merges behavioral, developmental, and relationship-oriented intervention), and PROMPT (a neuro-developmental approach for speech production disorders). Ten young, nonverbal children with autism were matched in pairs and randomized to treatment. They received 12 1-h weekly sessions of therapy and daily 1-h home intervention delivered by parents. Fidelity criteria were maintained throughout. Eight of the ten children used five or more novel, functional words spontaneously and spoke multiple times per hour by the conclusion of treatment. There were no differences in acquired language skills by intervention group. Initial characteristics of the best responders were mild to moderate symptoms of autism, better motor imitation skills, and emerging joint attention skills.