The goal of early autism screening is earlier treatment. We pilot-tested a 12-week, low-intensity treatment with seven symptomatic infants ages 7–15 months. Parents mastered the intervention and maintained skills after treatment ended. Four comparison groups were matched from a study of infant siblings. The treated group of infants was significantly more symptomatic than most of the comparison groups at 9 months of age but was significantly less symptomatic than the two most affected groups between 18 and 36 months. At 36 months, the treated group had much lower rates of both ASD and DQs under 70 than a similarly symptomatic group who did not enroll in the treatment study. It appears feasible to identify and enroll symptomatic infants in parent-implemented intervention before 12 months, and the pilot study outcomes are promising, but testing the treatment’s efficacy awaits a randomized trial.