Increased access to sterile syringes reduces the transmission of HIV, viral hepatitis and other infectious diseases, without increasing injection drug use. In Rhode Island, in 2000, syringes were legalized to reduce spread of disease but remained outlawed in Massachusetts until 2006. Drug users undergoing inpatient detoxification in Rhode Island and Massachusetts were surveyed about their syringe usage between October 2001 and August 2003. Two hundred forty-seven Rhode Island, and 226 Massachusetts inpatients completed surveys. Of these, 61% (n=151) from Rhode Island and 46% (n=105) from Massachusetts reported injecting within 6 months. Respondents from Rhode Island reported reusing a syringe in the last 30 days less often than Massachusetts respondents (0.35 versus 0.50; 95% CI on difference 0.01-0.29). Syringe re-use and sharing among drug injectors in Rhode Island was markedly lower than in Massachusetts. This difference is attributed at least in part to the legalization of non-prescription sterile syringes in Rhode Island in 2000. Laws and policies that increase legal syringe availability can decrease injection related transmission of HIV and other infectious diseases.