This paper reports findings on parental engagement in a community-based parent training intervention. As part of a randomized trial, 821 parents were offered group-based Triple P as a parenting skills prevention program. Program implementation was conducted by practitioners. The intervention was implemented between Waves 1 and 2 of a longitudinal study, with a participation rate of 69% and a retention rate of 96%. The study finds that a practitioner-led dissemination can achieve recruitment and completion rates that are similar to those reported in researcher-led trials. Second, the study found that different factors are associated with the various stages of the parental engagement process. Family-related organizational and timing obstacles to participation primarily influence the initial stages of parental involvement. The strength of neighborhood networks plays a considerable role at the participation and completion stages of parental engagement. The general course climate and the intensity of program exposure predict the utilization of the program several months after the delivery.