Objective: This study examined the efficacy of Hands-On Parent Empowerment-20 (HOPE-20) program. Methods: Eligible participants were parents residing in Hong Kong with target children aged 2 years attending nursery schools. Cluster randomized control trial was adopted, with 10 schools (110 participants) assigned to intervention group and 8 schools (63 participants) to control group using random number table, without blinding of participants. Intervention group attended 20 parent training sessions based on social learning theory. Children were individually assessed on preschool concepts and language skills. Parents completed child behavior and parental stress questionnaires. Results: Intention-to-treat analysis (173 participants and 18 schools) indicated improvement in primary outcomes: child preschool concepts (d = 0.70, 95% confidence interval [CI]: [0.38, 1.01]) and child behavior problems (d = 0.67, 95% CI: [0.35, 0.99]), together with language skills (d = 0.98, 95% CI: [0.65, 1.30]), and parental stress (d = 0.71, 95% CI: [0.39, 1.02]). Conclusions: The results suggested that HOPE-20 program was beneficial to Chinese families.