BACKGROUND/AIMS: Autoimmune chronic pancreatitis (AIP) is a clinically attractive entity because of its dramatic response to steroid therapy. But the long-term results after steroid therapy have not been reported yet in Korea. The purpose of this study was to assess the long-term results and prognosis after steroid therapy in patients with AIP. METHODS: We retrospectively analyzed the clinical, radiologic, and laboratory features and evaluated clinical outcomes in 19 patients with AIP who have been treated with oral corticosteroid. All patients were initially treated with prednisolone (30-40 mg/d) for 1 or 2 months. After the confirmation of clinical improvement in radiologic imaging and laboratory findings, the daily dose of prednisolone was then gradually tapered by 5-10 mg per month to the maintenance dose (2.5-7.5 mg/d). RESULTS: All the patients showed normalization or marked improvement in symptoms, laboratory and imaging findings after steroid therapy. There were 4 cases (21%) of recurrence during the mean follow-up period of 27 months. All the patients with recurrence responded to oral steroid again. Among the 10 patients with diabetes mellitus, seven patients were able to stop or reduce the medication for diabetes after completion of steroid therapy. The biliary stents were additionally inserted in 10 patients who showed distal common bile duct stricture and obstructive jaundice. The accompanying autoimmune diseases were also improved with oral corticosteroid. CONCLUSIONS: Steroid therapy is very effective for AIP and is also effective in the cases of recurrence. A definitive protocol of steroid therapy for AIP should be established in the future.