BACKGROUND AND OBJECTIVES: There is currently limited evidence on medium to long term community perceptions of public amenity where supervised injecting centres operate (SIC). Our objective was to investigate if community perceptions of public amenity have changed over time, comparing data collected prior to the establishment of the Sydney Medically Supervised Injecting Centre (MSIC), after 18 months and then following four and a half years of operation. METHODS: Telephone surveys were conducted among random samples of local residents and business operators in the vicinity of the MSIC at baseline, in the short term (following 18 months of operation) and in the medium term (following four and a half years of operation). Respondents were asked about their perceptions of drug use and its consequences in their neighbourhood, and to describe what they saw as advantages and disadvantages of the Sydney MSIC. Responses were compared over time and according to demographic characteristics of the survey participants. RESULTS: The survey was completed by 515, 540 and 316 residents and 269, 207 and 210 businesses in the 3 years respectively, with response rates generally above 75%. There was a significant decrease in the proportion of residents and business operators who reported having witnessed public injecting and publicly discarded injecting equipment, in the last month, with no significant change in proportions offered drugs for purchase. Residents were less likely to have seen public injecting in the last month if they were female, retired, lived over 500m from the MSIC or participated in the survey in 2005. Business operators who had witnessed public injecting or discarded needles and syringes in the last month were less likely to report either if located over 500m from the MSIC. Those businesses operating for over 5 years were more likely to have seen publicly discarded needles and syringes than those who had opened within the last year. Approximately 90% of both samples reported at least one advantage of the MSIC located in their area, citing the control of HIV/AIDS and hepatitis C and reduced overdose risk for injecting drug users among potential advantages. CONCLUSION: While the Sydney MSIC continues to attract political controversy, local residents and business operators perceived significant improvements in public amenity indicators since the opening of the service. Community members appear to be cognizant of both public health (potential reduction in blood borne virus transmission and overdose among injecting drug users) and public amenity benefits of the service.