To investigate community disposal of contaminated sharps by insulin-treated diabetes mellitus patients, we surveyed 144 patients. Twenty-three (16.0%) were non-contactable, leaving a study sample of 121, of whom 102 (84.3%) responded. Among the respondents 93.1% used lancets and 97.1% needles; 70.6% used lancets once or twice a day and 65.7% used needles twice a day. The majority said they had received no information on safe disposal of sharps. Of those recalling advice, most received it from diabetes nurse specialists. The majority of needle users used needle clippers and/or sharps bins for disposal. Most of the lancet users resorted to drinks cans/bottles or domestic waste. There were statistically significant differences in practices between patients receiving and not receiving advice on sharps disposal (odds ratio [OR] 6.36 [95% CI 2.04-23.28] p = 0.0007 for needle disposal and OR 15.41 [95% CI 3.57-90.12] p = 0.00001 for lancet disposal). There were also statistically significant differences among needle users using and not using needle clippers and/or sharps bins according to the interval since diagnosis and the frequency of needle use per day. This study identifies a need for a standardised approach to sharps disposal supported by an effective method of disseminating information, and a need for advice on auditing its impact.