Hand washing is the most important preventative measure for the reduction of contagious disease. Although hand washing is easy to perform, non-adherence is a ubiquitous problem. Several studies have demonstrated the effectiveness of multi-component intervention packages to improve hand washing among employees; however, interventions are limited to acute settings, are often implemented for a short period of time, and rarely, if ever, include information on long-term effectiveness. The purpose of the current study was to utilize a behavior analytic approach to determine the stimulus conditions under which hand washing should occur, and to assess and then implement a long-term monitoring system among direct care workers in a large, non-acute inpatient unit. A single-case repeated measures reversal design was used to evaluate the effectiveness of two interventions aimed at improving hand washing adherence. A lottery was found to be effective in increasing hand hygiene for 2-years with 170 staff.