Following an anonymous survey on health und substance use problems in 2004, a prevention program for workers at a Bavarian rehabilitation clinic was initiated. Its efficiency was evaluated by a follow-up study in 2007. The initial analysis had indicated a high rate of substance abuse. Young female employees had been identified as one of the risk groups for alcohol consumption and professional discontent. Based on these findings, a special prevention program was established. The follow-up study revealed some improvements with respect to health und substance abuse, including a significant reduction in average alcohol consumption. These findings indicate that prevention programs at the workplace are both possible and effective.