During the last two decades illicit drug use in Belgrade has been changed.Previously, one of the most common methods of illicit heroin use was via intravenous injection. In 1987, injecting drug, as main consumption patterns was accepted by 90,6% of patients, although intravenous administration fell to 75,5% in 1995.

The aim of the study was to observe if the main pattern of heroin consumption had changed lately.

The study included 382 illicit drug users (mean age 28,8 ± 4,7; both gender) treated in Special Hospital for Addiction, Belgrade in period of a year (Sept. 2009–2010).We used data from Pompidou questionnaire and calculated prevalence through standard survey technique.

A total of 94,5% respondents reported a lifetime prevalence of heroin as a main drug, 1,1% of other opiates, 0,3% of cocaine and amphetamine. More than 92,7% of respondents used heroin in the last month regularly. The lifetime prevalence consumption mode for intranasal use was 44,3%, injecting 39,8% and smoking/ inhaling 13,9%.First injectable route experience is reported for age 17–19 = 11.9%; for 20–22 = 25.6%; for 23–26 = 30-3%. The total number of 79,8% reported negative HIV testing result, 0,5% positive result.

The consumption model changed in last 10 years and our study confirmed significant diversity. Intranasal administration linked with young population of heroin addicts, who never or rarely use injectable route with low level of HIV infection. Older addicts prefer intravenous use and often change to intranasal route later, for safety or damaged process of peripheral blood vessel.