Background: Recent studies indicate that parent education programs that include content to enhance parents' mental states may prove efficacious in improving parenting behavior and child outcomes. Objective: This study presents findings from a national evaluation of the "Active Parenting First Five Years" (FFY) program. This group-based parent education program utilizes a video-supported curriculum and is designed to promote responsive parenting and healthy development in children under the age of 5, with a unique emphasis on caregivers' mental states (i.e., mindfulness, executive function) and parent well-being. Method: A total of 213 (132 to test hypothesis 1) primary caregivers of children ages 0-4 participated. This study introduces a novel "Inclusive Randomized Controlled Trial" design for establishing treatment and comparison groups. Parent and child behavior were reported one month prior to the program beginning (Time 1/Control Survey), at the beginning of the program (Time 2/Pre-Survey), and at the conclusion of the program (Time 3/Post Survey). Results: Pre- to post-test analyses showed significant increases in caregiver reported responsive parenting, developmental knowledge, parenting efficacy, mindfulness, overall positive child behavior, child prosocial behavior, and decreased parenting stress. Analysis of the treatment and control study groups detected group differences indicative of program effects for the parenting outcomes of mindfulness, parenting efficacy, and parenting stress. Conclusions: These findings illustrate the initial effectiveness of the FFY program, the potential usefulness of the "Inclusive Randomized Controlled Trial" in community samples, and emphasize the need for parental well-being to receive increased consideration in parenting intervention designs and curricula.