This was a multicentre study with risk perception as the theoretical framework, investigating if risk behaviours change when injecting drug users (IDUs) are aware of their hepatitis C virus (HCV) status and had assessed the health consequences with HCV infection. Two hundred and thirteen participants aged 15-40 y were analysed. Sharing of needles and of other injecting equipment were common both among participants who reported HCV-positive status (74%, 95% confidence interval (CI) 65.3-80.1%) and among those who reported HCV status unknown (68%, 95% CI 56.0-78.4%). Participants associating very severe health consequences with HCV infection and those who did not know of any health consequences with HCV infection shared needles at almost the same rate (78%, 95% CI 62.5-87.7 vs 69%, 95% CI 8.0-78.9, respectively). Sharing of other injecting equipment was most common among participants with verified HCV-positive status (adjusted risk ratio 5.64, 95% CI 2.64-12.07). Knowledge of HCV status and assessment of health consequences with HCV infection were not enough to change injecting risk behaviours. Sharing of other injecting equipment was a more important risk factor than sharing needles for participants with verified HCV-positive status. It is suggested that professionals engage IDUs in risk analysis and open a dialogue about assessment in order to identify, quantify and characterize risks.