The objective of the research was to assess the effects of geographic proximity on the utilization of syringe exchange among injection drug users (IDUs) in New York City. Between 1994 and 1996, 805 IDUs were interviewed with a structured questionnaire. Geographic proximity was defined as living within a ten-minute walk. Eighty-one per cent of IDUs who lived close typically used a syringe exchange compared to 59% of those who lived further away. In multiple logistic regression analysis, those who lived close remained (adjusted odds ratio of 2.89; 95% CI 2.06 to 4.06, p = 0.001) more likely to use syringe exchange. Those who lived close were less likely to have engaged in receptive syringe sharing at last injection (adjusted odds ratio = 0.45, 95% CI 0.24 to 0.86, p = 0.015). In conclusion, locating exchange services in areas convenient to large numbers of IDUs may be critical for prevention of HIV infection.