BACKGROUND & AIMS: We report the first real-life results of the sofosbuvir+daclatasvir combination in hepatitis C virus (HCV) genotype 1 infected patients. METHODS: The France REcherche Nord&Sud Sida-hiv Hépatites (ANRS) CO22 HEPATHER "Therapeutic options for hepatitis B and C: A French cohort" is a multicentre observational cohort which aims to include 15,000 HCV- and 10,000 HBV-infected patients. We selected all participants (n=768) with a HCV genotype 1 who initiated sofosbuvir (400mg/day) and daclatasvir (60mg/day) before October 1st 2014, with or without ribavirin (1-1.2g/day) for a duration of 12weeks or 24weeks. The main endpoint criterion was sustained virological response at 12weeks (SVR12), defined by the absence of detectable HCV-RNA 12weeks after the last treatment intake. Missing SVR12 measurements were imputed using SVR24 measurements (n=45), otherwise considered as virological failure (n=18). RESULTS: A SVR12 was obtained in 729/768 (95%) patients, ranging from 92% (12-week sofosbuvir+daclatasvir) to 99% (24-week sofosbuvir+daclatasvir+ribavirin). The SVR12 rates did not significantly differ between the 24-week (550/574 (96%)) and the 12-week (179/194 (92%); p=0.0688) durations or between regimens with (165/169 (98%)) or without ribavirin (564/599 (94%); p=0.0850). The SVR12 rate was greater than 97% in non-cirrhotic patients irrespective of the treatment duration or the addition of ribavirin. Among cirrhotic patients, the SVR12 rate was higher with 24 than 12-week regimen (423/444 (95%) vs. 105/119 (88%); p=0.0054). CONCLUSION: The sofosbuvir+daclatasvir combination is associated with a high rate of SVR12 in patients infected by genotype 1, with an optimal duration of 12weeks in non-cirrhotic and 24weeks in cirrhotic patients. The number of patients receiving ribavirin was too low to adequately assess its impact. LAY SUMMARY: The sofosbuvir+daclatasvir combination of antiviral drugs is associated with a high rate (95%) of viral eradication in patients infected by HCV genotype 1. The best duration of a ribavirin-free sofosbuvir+daclatasvir combination seems to be 12weeks in non-cirrhotic patients and 24weeks for those with cirrhosis. Clinical trial number: NCT01953458.