ObjectiveTo determine if introducing finger puppets in the primary care setting during infancy improves parenting and language outcomes at 12 months. MethodsIntervention cohorts were enrolled at ages 2 (early) and 6 (late) months, given a puppet, and followed two weeks later to assess dosage. High dosage was defined as using the puppet daily. At 12 months, a usual care cohort was enrolled and outcome measures were collected for all participants, including maternal depression (PHQ-9), the cognitive home environment (StimQ-T), preverbal skills (CSBS-DP-IT), and vocabulary development (CDI SF). ResultsOf 413 families screened, 248 (60%) were eligible, 180 (73%) enrolled, and 154 (86%) completed the 12-month visit. Most children (84%) were on government-sponsored insurance. There were no differences between early and late intervention outcomes. In intention-to-treat analysis, the intervention cohorts scored better than usual care on the Availability of Learning Materials (ALM) (5.50 vs. 5.02, p = 0.04) and Parental Involvement in Developmental Advance (PIDA) (8.30 vs. 7.58, p = 0.02) StimQ-T subscales and receptive vocabulary (CDI SF English) (61.0 vs. 50.1, p = 0.05). In per protocol analysis, high dosage scored better than low dosage and usual care on the StimQ-T ALM (5.83, 5.08, 5.02, p = 0.01), preverbal communication (CSBS-DP-IT) (72.3, 57.2, 59.2, p = 0.01), and receptive vocabulary (CDI SF English) (73.4, 56.1, 50.1, p = 0.0002). ConclusionsFinger puppets distributed in infancy were associated with an enhanced cognitive home environment and better preverbal and receptive language at 12 months, especially for families using the puppet daily. Additional study should determine if impacts are generalizable and maintained.