BACKGROUND: In clinical trials, a pangenotype direct-acting antiviral (DAA) regimen consisting of glecaprevir (GLE) and pibrentasvir (PIB) exhibited high virologic efficacy and tolerability in patients with hepatitis C virus (HCV) infection. This study sought to confirm these findings in real-world settings, focusing on patients with cirrhosis, history of DAA failure, or HCV genotype 3 who were treated with a 12-week regimen in a large multicenter study from Japan. METHODS: In a nationwide multicenter prospective cohort study, we analyzed background characteristics, tolerability, and treatment outcome of patients who underwent a 12-week GLE/PIB regimen. RESULTS: Of 1190 patients, 509 (42.8%) underwent the 12-week regimen, and the remaining patients underwent an 8-week regimen. The rate of sustained virologic response (SVR) of patients treated with the 12-week regimen was 99.0%, comparable with that of patients treated with the 8-week regimen. The adverse events were observed in 29.1% of patients. The main adverse event was pruritus, which was observed in 14.7%. Ten patients (2.0%) discontinued therapy during treatment period. CONCLUSION: The 12-week GLE/PIB regimen was well-tolerated with high virologic efficacy in patients with cirrhosis, experience of DAA, or HCV genotype 3; tolerability and SVR rate were comparable with those of DAA-naïve, non-cirrhotic, non-genotype 3 patients who underwent 8-week regimen.