INTRODUCTION: Treatment for Hepatitis C Virus (HCV) aims to achieve a cure from disease as defined by a sustained virological response (SVR). The development of new generation direct acting antivirals (DAAs) with much higher SVR rates than interferon-containing regimens has dramatically improved the prospects for people infected with HCV including improved clinical outcomes and survival and lower all-cause mortality. Phase 3 studies have demonstrated that the combination of sofosbuvir and ledipasvir (SOF/LDV)±ribavirin (RBV) achieves SVR>90% in treatment-naïve and experienced patients with or without cirrhosis with genotype 1 (G1) HCV. Although CTs are the gold standard in evaluating the efficacy of DAAs, they are conducted under controlled settings which may not be generalizable across real-world (RW) settings. Robust observational Irish data is essential for evaluating and understanding the true effectiveness of HCV treatments and can provide valuable information for Irish health policy and decision makers regarding resource allocation. OBJECTIVES: To report the RW outcomes of G1-HCV patients treated with SOF/LDV in Ireland and to compare SVR RW performance against efficacy data from CTs. METHODS: Data were extracted from the Irish Hepatitis C Outcomes and Research Network (ICORN) national HCV treatment registry. Descriptive statistics were produced for final outcomes (relapse, discontinuation and SVR rates) of all patients with G1 HCV, irrespective of cirrhotic or pre-treatment status RESULTS: Outcome data were available for 133 G1 HCV patients (96% cirrhotic) treated with SOF/LDV±RBV. Eleven patients (8.27%) prematurely discontinued treatment, of whom 5 patients died on treatment and 2 discontinued due to adverse events. The overall SVR12 rate was 86.47% (115/133) with an overall relapse rate of 5.26% (7/133). CONCLUSIONS: HCV G1 patient response rates to combination SOF/LDV in Ireland are comparable to other ‘real-world’ and CT data sources.