Background/Aims: Erlotinib and gemcitabine combined chemotherapy is becoming the treatment of choice in ad-vanced pancreatic cancer. We evaluated the effectiveness of treatment with erlotinib plus gemcitabine and the prognostic factors for chemotherapeutic response in Korean pancreatic cancer patients. Methods: Sixty-nine patients with advanced pancreatic cancer who were treated with daily erlotinib 100 mg orally and gemcitabine 1,000 mg/m2/30 min intrave-nous infusion on days 1, 8, and 15 of each 4-week cycle from 2006 to 2009 were included in this study. This study was a phase II single-center trial. Results: All 69 patients with advanced pancreatic cancer were chemotherapy-naive. The objective response rate was 18.8%, and the overall tumor-stabilization rate was 49.2%. The median overall sur-vival was 7.7 months (95% confidence interval [CI], 6.0 to 9.4 months). The median progression-free survival was 1.9 months (95% CI, 1.4 to 2.5 months). Prognostic factors for good chemotherapeutic response were good performance status and the presence of skin rash during chemotherapy. Patients with lower performance scores showed worse che-motherapeutic responses (odds ratio [OR], 7.6; 95% CI, 2.4 to 24.8). Poor responses were predicted by the absence of skin rash during chemotherapy (OR, 3.0; 95% CI, 1.4 to 6.3). Conclusions: Erlotinib and gemcitabine chemotherapy is a tolerable treatment regimen and has a favorable therapeutic effect in Korean patients with advanced pancreatic cancer. (Gut Liver 2013;7:611-615)