This study was performed to evaluate the efficacy of a triple therapy in older Japanese patients; telaprevir (TVR) was added to pegylated interferon α2b and ribavirin.This prospective study enrolled 120 genotype 1b patients with chronic hepatitis C who received 12weeks of triple therapy followed by a 12-week dual therapy that included pegylated interferon α2b and ribavirin. Patients were categorized according to age: group A, 64 patients aged >60 and group B, 56 patients aged ⩽60. Serum HCV RNA levels were monitored by COBAS TaqMan HCV test.The rates of undetectable HCV RNA at week 4 (rapid virological response, RVR) were 73.4% in group A and 73.2% in group B. No significant difference in sustained virological response (SVR) was found between groups A (76.6%) and B (83.9%) (p=0.314). The SVR rates for patients with interleukin 28B (IL28B) (rs8099917) TT allele (89.4% and 91.9% for groups A and B) were significantly higher than for those with the IL28B TG/GG allele (41.2% and 68.4%, respectively) (both p<0.05). Multivariate analysis extracted IL28B TT and RVR as independent factors associated with SVR. Adverse effects resulted in treatment discontinuation by 12.5% in each group. Hemoglobin decrease significantly differed between groups A and B: the decrease to ⩾100g/L, to 85 – <100g/L, and to <85g/L, was 9.4%, 40.6%, and 50% in group A patients, respectively, and 41.1%, 25%, and 33.9% in group B patients, respectively (p=0.0006).TVR-based triple therapy can be successfully used to treat older patients with genotype 1b chronic hepatitis C.