Motivational interviewing is an empirically supported treatment for drug and alcohol problems. Training in this approach is very popular, although previous studies have identified that the acquisition of key skills is challenging and that postworkshop supervision inputs are helpful. This pilot trial investigated the training of adolescent drug treatment practitioners, comparing a group who received immediate training against a delayed training study condition. Training and supervision were found to have no impact upon skill levels as measured by the Motivational Interviewing Treatment Integrity Version 2, with the exception of a very specific effect on motivational interviewing spirit. Motivational interviewing was not easy to learn for these practitioners. Progress made indicates the importance of ongoing supervision, and for high level skill acquisition to occur requires more intensive support of learning from ongoing practice than was used here.