Our cluster randomized controlled trial tested, respectively, 2 brief interventions to promote more appreciation and less criticism in Hong Kong Chinese parents toward their children and to enhance family well-being. We randomized 56 primary schools and community service centers (clusters of parents of primary grades 3-6 students) to the more appreciation (MA) or less criticism (LC) intervention arms, or fruit and vegetable control arm (FV). A total of 803 parents received a 2-hr workshop on increasing appreciation (19 clusters, n = 270), reducing criticism (21 clusters, n = 336), or increasing fruit and vegetable consumption (16 clusters, n = 197) and were assessed at baseline, immediately after the workshop, at 2 weeks, and at 6 weeks. Primary outcomes were parents' frequency of appreciation and criticism behaviors. Secondary outcomes were family well-being and potential behavioral determinants proposed by the Health Action Process Approach, including outcome expectancies, self-efficacy, intention, and planning behavior. At 6 weeks, the MA and LC arms reported greater increases in appreciation behavior than the FV arm, and the LC arm reported greater decreases in criticism than the FV arm, with small effect sizes. Specific improvements were also observed in the behavioral determinants at various time points compared with the FV arm. Similar improvements in family well-being were observed across all arms. Our findings were the first to show that brief Health Action Process Approach-based workshops on Chinese parents were effective in promoting positive parental behaviors. (PsycInfo Database Record (c) 2020 APA, all rights reserved).