OBJECTIVES: One criticism of prescription drug monitoring programs (PDMPs) is that they may compromise access to appropriate therapy, called the ‘chilling effect’. Previous research evaluating the impact of benzodiazepine monitoring in New York (NY) reported that benzodiazepine use dramatically decreased and remained stable at that lower level. In January of 2008, South Carolina (SC) implemented a PDMP that included benzodiazepine monitoring.  We examine the impact of the PDMP on benzodiazepine use by comparing use before and after implementation.   METHODS: We used a publically available, private insurance claims database containing records from January 2007 to December 2009. Continuously eligible SC residents between ages 19-65 were analyzed. Logistic regression models examined the likelihood of filling a benzodiazepine prescription during each month. Control variables included PDMP status (active vs. inactive) and recipient characteristics (age, gender, race, and education). Interaction terms were included to determine if the PDMP had a differential impact based on demographics. Statistical analysis was conducted in STATA v12.0. RESULTS: A total of 20,260 recipients were included. Regression results showed recipients have higher odds of filling a benzodiazepine prescription when the PDMP is active vs. inactive (p-value <0.001; CI 1.377-2.023). PDMP implementation was shown to more negatively impact the likelihood of females filling a benzodiazepine prescription compared to males (p-value 0.009; CI 0.8272-0.9727) and recipients between 50-65 years compared to recipients 19-29 (p-value 0.034; CI 0.7029 -0.9866). CONCLUSIONS: In this population, the implementation of the PDMP did not create a ‘chilling effect’ by decreasing the likelihood recipients would fill a benzodiazepine prescription; a contrast to previous findings from NY.  Our study is limited by the use of a pre/post design with only three years of data from a privately insured population. Further research should focus on additional states and populations to better determine the impact of PDMPs on benzodiazepine use.