BACKGROUND: Prior single site evaluations of PriCARE, a 6-session group parent training, demonstrated reductions in child behavioral problems and improvements in positive parenting attitudes. OBJECTIVE: To measure the impact of PriCARE on disruptive child behaviors, parenting stress, and parenting attitudes in a multisite study. METHODS: Caregivers of children 2- to 6-years-old with behavior concerns recruited from 4 pediatric primary care practices were randomized 2:1 to PriCARE intervention (n=119) or waitlist control (n=55). 79% of caregivers identified as Black and 59% had annual household incomes under $22,000. Child behavior, parenting stress, and parenting attitudes were measured at baseline and 2-3 months after intervention using the Eyberg Child Behavior Inventory (ECBI), Parenting Stress Index (PSI), and Adult-Adolescent Parenting Inventory-2 (AAPI-2). Marginal standardization implemented in a linear regression compared mean change scores from baseline to follow-up by treatment arm while accounting for clustering by site. RESULTS: Mean change scores from baseline to follow-up demonstrated greater improvements (decreases) in ECBI problem scores but not intensity scores in the PriCARE arm compared to control, [problem: -4.4 (-7.5, -1.2) versus -1.8 (-4.1, 0.4), p=0.004; intensity: -17.6 (-28.3, -6.9) versus -10.4 (-18.1, -2.6), p=0.255]. Decreases in parenting stress were greater in the PriCARE arm compared to control [-3.3 (-4.3, -2.3,) versus 0 (-2.5, 2.5), p=0.025]. Parenting attitudes showed no significant changes (all p>0.10). CONCLUSIONS: PriCARE showed promise in improving parental perceptions of the severity of child behaviors and decreasing parenting stress but did not have an observed impact on parenting attitudes.