Objectives Rural primary care practitioners (PCPs) have a pivotal role to play in frontline pediatric mental health care, given limited options for referral and consultation. Yet they report a lack of adequate training and confidence to provide this care. The aim of this study was to test the effectiveness of the Practitioner Training in Child and Adolescent Psychiatry (PTCAP) program, which was designed to enhance PCPs’ pediatric mental health care confidence. The program includes brief therapeutic skills and practice guidelines PCPs can use to address both subthreshold concerns and diagnosable conditions, themselves. Methods The study design was a pilot, cluster-randomized, multicenter trial. Practices were randomly assigned to intervention ( n practices = 7; n PCPs = 42) or to wait-list control ( n practices = 6; n PCPs = 34). The intervention involved 8 hr of training in practice guidelines and brief therapeutic skills for depression, anxiety, attention deficit hyperactivity disorder, and behavioral disorders with case discussion and video examples, while the control practiced as usual. A linear random-effects model controlling for clustering and baseline was carried out on the individual-level data to examine between-group differences in the primary (i.e., confidence) and secondary (i.e., attitude and knowledge) outcomes at 1-week follow-up. Results Findings were a statistically significant difference in the primary outcomes. Compared to the control group, the intervention group indicated significantly greater confidence in managing diagnosable conditions ( d = 1.81) and general concerns ( d = 1.73), as well as in making necessary referrals ( d = 1.27) and obtaining consults ( d = 0.74). While the intervention did not significantly impact secondary outcomes (attitudes and knowledge), regression analysis indicated that the intervention may have increased confidence, in part, by ameliorating the adverse impact of negative mental health care attitudes. Conclusion PTCAP enhances PCPs’ child/youth mental health care confidence in managing both general and diagnosable concerns. However, an 8-hr session focused on applying brief therapeutic skills was insufficient to significantly change attitudes and knowledge. Formal testing of PTCAP may be warranted, perhaps using more intensive training and including outcome assessments capable of determining whether increased PCP confidence translates to more effective management and better patient outcomes.