To determine factors influencing enrollment for community pharmacists registered and not registered in Ohio's prescription monitoring program (PMP), the Ohio Automated Rx Reporting System (OARRS); to identify association of OARRS enrollment with demographics, availability of Internet access at work, educational background, and/or previous PMP education received; and to compare knowledge of OARRS for enrollees versus nonenrollees.Descriptive, nonexperimental, cross-sectional study.Ohio in November and December 2008.Pharmacists licensed and living in Ohio with a valid e-mail address on file with the state board of pharmacy.Online survey developed and administered via Zoomerang.Factors influencing enrollment for community pharmacists registered and not registered with OARRS.2,511 complete responses were recorded, and 1,434 respondents indicated community pharmacy as their primary practice setting. Pharmacists not registered with OARRS noted "time available to access the OARRS report" as the top factor influencing their decision not to enroll in OARRS. Pharmacists registered with OARRS noted "being able to assist with decreasing doctor shopping" as the top factor influencing their decision to enroll in OARRS.Factors influencing enrollment as indicated by pharmacists not registered with OARRS should be the primary focus of initial efforts to increase enrollment.