Although progress has been made in developing a scientific basis for alcohol screening and brief intervention (SBI), training packages are necessary for its widespread dissemination in primary care settings. This paper evaluates a training package developed for the Cutting Back SBI program. Three groups of medical personnel were compared before and after SBI training: physicians (n = 44), medical students (n = 88), and non-physicians (n = 41). Although the training effects were at times dependent on group membership, all changes were in a direction more conducive to implementing SBI. Physicians and medical students increased confidence in performing screening procedures, and students increased self-confidence in conducting brief interventions. Non-physicians perceived fewer obstacles to screening patients after training. Trained providers reported conducting significantly more SBI than untrained providers, and these differences were consistent with patients' reports of their providers' clinical activity. Thus, when delivered in the context of a comprehensive SBI implementation program, this training is effective in changing providers' knowledge, attitudes, and practice of SBI for at-risk drinking.