BackgroundLimited data exists about treatment outcomes in nationwide hepatitis C virus (HCV) elimination programs where injection drug use (IDU) is the main mode of transmission. In 2016 Iceland initiated the HCV elimination program known as Treatment as Prevention for Hepatitis C (TraP HepC). Factors associated with HCV cure in this population are examined. MethodsUnrestricted access was offered to direct acting antiviral agents (DAAs). Testing and harm reduction was scaled up and re-treatments were offered for those who did not attain cure. Cure rates for the first 36 months were assessed and factors associated with failure to achieve cure analysed using multivariable logistic regression. ResultsTreatment was initiated for 718; 705 consented for the study. Median age was 44 years (IQR 35–56), history of IDU reported by 593 (84.1 %), recent IDU by 234 (33.2 %); 48 (6.8 %) were homeless. Of 705 patients, 635 achieved cure (90.1 %) during the first treatment. A total of 70 (9.9 %) patients initiated two or more treatments, resulting in 673 participants cured (95.5 %). By multivariable analysis, homelessness was the only statistically significant independent factor associated with not achieving cure (OR 2.67, 95 % CI 1.32–5.41) after first treatment attempt. ConclusionBy reengagement in care and prompt retreatment when needed, a cure rate of 95.5 % was achieved. Unstable housing, a potentially actionable factor is associated with poor outcome.