This study used an experimental design to compare three groups that received supervisor training with a control group that received no training. A total of 403 supervisors were randomly assigned to one of the four study groups and tested immediately after training and one year following training. Supervisors who received training showed increased knowledge of the EAP (p<.001) at one-year followup as well as more consultations (p<.05) with and referrals (p<.01) to the EAP compared to the control group. However, only those supervisors who received previous training showed a significant increase in their referrals to the EAP (p<,01). This study provides empirical support for the efficacy of EAP training for supervisors. In addition, these data suggest that supervisor training should be viewed as a "process" in which multiple training sessions are necessary for supervisors to transfer knowledge to on-the-job behavior.