OBJECTIVES: Prescription drug monitoring programs (PDMPs) have been implemented by states as a means to reduce abuse and diversion of controlled substances (CS).  Relatively little is known, however, about their effectiveness in achieving these goals.  The purpose of this project was to assess the perceived impact of the Kentucky All Schedule Prescription Electronic Reporting program (KASPER) on CS prescribing behavior and to evaluate the perceived effectiveness of KASPER as a tool to reduce drug abuse, diversion and doctor shopping. METHODS: A sample of two thousand prescribers, including physicians, advanced practice nurses and dentists, was randomly selected from a list of over 4,000 registered with KASPER.  The prescribers were contacted via mail to complete a survey.  A reminder postcard and second survey was sent to non-responders two weeks after the first mailing.   Five hundred fifty-seven (557) responses were received from prescribers for a response rate of approximately 28%. Responses were coded and descriptive analysis was conducted in STATA v11. RESULTS: The majority (89%) of prescribers responding to the survey were physicians who reported using a mean of 19.7 KASPER reports monthly for treatment decisions.  89% of respondents indicated that information in the reports impacts their treatment decisions. One-half of respondents indicated no change in CS prescribing behavior over the past year as a result of KASPER while 35% indicated a decrease in CS prescribing and 13% indicated an increase in CS prescribing. 96% of respondents believe KASPER is an effective tool for reducing abuse and diversion while 95% believe it is an effective tool to reduce doctor shopping. CONCLUSIONS: Respondents that use KASPER regularly find the information in reports valuable for making treatment decisions. Overall, the vast majority of respondents perceive KASPER as an effective tool to reduce drug abuse, diversion and doctor shopping.   Further research is needed to directly assess the effectiveness of PDMPs.