Despite efforts to expand use of evidence-based practice (EBP) within child and adolescent mental health clinics, these practices continue to be underutilized, partially due to a lack of quality training for clinicians. This article describes the second iteration of an evidence-based assessment and treatment seminar for staff clinicians and trainees in an academic medical center. The seminar was held in-person over 11 weeks in 90-min sessions and covered assessments and interventions for the most common referral concerns in our outpatient clinic. Clinicians and supervisors completed measures before and after the seminar to assess the impact of the seminar on attitudes, knowledge, skill, and frequency of use of EBP. Although, on average, the majority of clinicians and their supervisors reported that knowledge and clinically appropriate use of interventions and assessments increased after the seminar, differential effects were found for progress monitoring versus assessment for diagnostic evaluation. This study demonstrates the potential of using in-house clinic leaders and supervisors who are trained in delivering EBPs as a source of support for incoming clinicians. We highlight many practical considerations that may be helpful to consider when implementing a training seminar to increase the use of EBP.