Abstract: Currently, the most important risk factor for hepatitis C virus (HCV) infection in Europe is intravenous drug use. To establish a better insight into the epidemiology of hepatitis C among intravenous drug users (IVDUs) in western European countries a systematic review on the prevalence of hepatitis C markers and their determinants was performed. Reports were identified by searches on Medline and on the internet and by screening reference lists of selected papers. The prevalence rates of anti-HCV in western European IVDUs reported in the 66 studies selected for analysis, ranged between 37 and 98%. No relation was found between prevalence rates and mean age, mean duration of intravenous drug use, geographical area, setting of the study, method of recruitment or the year(s) of collection of samples. Eleven studies concerning the prevalence of HCV-RNA in hepatitis C-infected IVDUs were selected for analysis. Prevalence rates ranged from 26 to 86%. Based on five studies, a statistically significant positive linear relation was found between the mean age of study population and the prevalence of HCV-RNA. Our analysis revealed considerable variation in prevalence rates of hepatitis C markers among IVDUs in western Europe. We found no conclusive explanation for this variability. Further research investigating the dynamics of the hepatitis C epidemic in IVDUs is necessary.