This paper presents the rationale and methods for a randomized controlled evaluation of webbasedtraining in motivational interviewing, goal setting, and behavioral task assignment.Web-based training may be a practical and cost-effective way to address the need for largescalemental health training in evidence-based practice; however, there is a dearth of wellcontrolledoutcome studies of these approaches. For the current trial, 168 mental healthproviders treating post-traumatic stress disorder (PTSD) were assigned to web-based trainingplus supervision, web-based training, or training-as-usual (control). A novel standardizedpatient (SP) assessment was developed and implemented for objective measurement ofchanges in clinical skills, while on-line self-report measures were used for assessing changesin knowledge, perceived self-efficacy, and practice related to cognitive behavioral therapy(CBT) techniques. Eligible participants were all actively involved in mental health treatmentof veterans with PTSD. Study methodology illustrates ways of developing training content,recruiting participants, and assessing knowledge, perceived self-efficacy, and competencybasedoutcomes, and demonstrates the feasibility of conducting prospective studies oftraining efficacy or effectiveness in large healthcare systems.