OBJECTIVE: Report long-term outcomes of the NOURISH randomized controlled trial (RCT), which evaluated a universal intervention commencing in infancy to provide anticipatory guidance to first-time mothers on "protective" complementary feeding practices that were hypothesized to reduce childhood obesity risk. METHODS: The NOURISH RCT enrolled 698 mothers (mean age 30.1 years, SD = 5.3) with healthy term infants (51% female). Mothers were randomly allocated to usual care or to attend two 6-session, 12-week group education modules. Outcomes were assessed 5 times: baseline (infants 4.3 months); 6 months after module 1 (infants 14 months); 6 months after module 2 (infants 2 years) and at 3.5 and 5 years of age. Maternal feeding practices were self-reported using validated questionnaires. BMI Z-score was calculated from measured child height and weight. Linear mixed models evaluated intervention (group) effect across time. RESULTS: Retention at age 5 years was 61%. Across ages 2 to 5 years, intervention mothers reported less frequent use of nonresponsive feeding practices on 6 of 9 scales. At 5 years, they also reported more appropriate responses to food refusal on 7 of 12 items (Ps ≤ .05). No statistically significant group effect was noted for anthropometric outcomes (BMI Z-score: P = .06) or the prevalence of overweight/obesity (control 13.3% vs intervention 11.4%, P = .66). CONCLUSIONS: Anticipatory guidance on complementary feeding resulted in first-time mothers reporting increased use of protective feeding practices. These intervention effects were sustained up to 5 years of age and were paralleled by a nonsignificant trend for lower child BMI Z-scores at all postintervention assessment points.