Purpose. This study was designed to compare expert consultant trainers and less experienced, in-house trainers in providing basic training in motivational interviewing (MI) for juvenile corrections employees.Methods. Trainees (n = 1,552) attended a 3-day workshop administered by either a member of the Motivational Interviewing Network of Trainers (MINT) or a corrections staff member who had been trained by a MINT trainer.Results. Pre-to post-test MI knowledge and skill gains did not vary between MINT expert and internal trainers, and increased for both groups. MINT trainees were more motivated to learn MI and expected it to be more effective in their work compared with those trained by corrections staff. MINT trainers were perceived as more knowledgeable about the topic, whereas corrections staff trainers were rated as better at utilizing handouts and visual aids. The groups did not differ on other measures of trainee satisfaction.Conclusions. These data suggest that a train-the-trainers model, in which expert consultants provide initial trainings to develop a pool of staff to provide subsequent trainings, may be as effective as a model that relies exclusively on expert trainers.Correctional officers (COs) and other professionals who work in juvenile or adult prisons face chronic stressors due to the unique tasks that are a daily part of their jobs (Brough & Williams, 2007;McCraty, Atkinson, Lipsenthal, & Arguelles, 2003). Listening to the problems of the offenders they supervise, monitoring behaviour, conducting facility counts, responding to emergencies, identifying gang activity, providing counselling and motivation, and ensuring the safety of inmates and staff all demand a wide variety of skills (Demmo, 2010;Khan, 2009). Pre-service and in-service training to enhance or maintain needed skills are usually conducted by trainers who have worked in the same or similar systems and understand the demands and pressures of working in prisons. Most county and state systems offer their own training academies, usually staffed by their own * Correspondence should be addressed to Neal Doran, PhD, UCSD, Department of Psychiatry, 3350 La Jolla Village Drive, San Diego, CA 92161, USA (e-mail: nmdoran@ucsd.edu employees (Khan, 2009). Outside experts with specific knowledge have been utilized for training and have been well-received (Parker, 2009) but trainees can be sceptical of outsiders' understanding of the prison environment (Crawley, 2004). To date, no studies have compared in-house trainers with outside expert trainers in correctional settings, particularly with the same training topic. The unique opportunity to do so presented itself when a large juvenile correctional system utilized outside expert trainers in motivational interviewing (MI) who then trained trainers who worked within the system.MI is an evidence-based counselling or communication style typically used in behaviour change interventions; it focuses on empathic, collaborative discussion of reasons for and ambivalence about behaviour change (Miller & Roll...