Diabetes mellitus (DM) is a common complication of chronic pancreatitis (CP) and increases the mortality. The identification of risk factors for DM development may contribute to the early detection and potential risk reduction of DM in patients with CP.Patients with CP admitted to Changhai Hospital (Shanghai, China) from January 2000 to December 2013 were enrolled. Cumulative rates of DM after the onset of CP were calculated by Kaplan-Meier method. Risk factors for DM development after the diagnosis of CP were identified by Cox proportional hazards regression model.A total of 2011 patients with CP were enrolled. During follow-up (median duration, 22.0 years), 564 patients developed DM. Cumulative rates of DM 20 and 50 years after the onset of CP were 45.8% (95% confidence interval [CI], 41.8%-50.0%) and 90.0% (95% CI, 75.4%-97.7%), respectively. Five risk factors for DM development after the diagnosis of CP were identified: male sex (hazard ratio [HR], 1.51; 95% CI, 1.08-2.11), alcohol abuse (HR, 2.00; 95% CI, 1.43-2.79), steatorrhea (HR, 1.46; 95% CI, 1.01-2.11), biliary stricture (HR, 2.25; 95% CI, 1.43-3.52), and distal pancreatectomy (HR, 3.41; 95% CI, 1.80-6.44).In conclusion, the risk of developing DM in patients with CP is not only influenced by the development of biliary stricture and steatorrhea indicating disease progression, and inherent nature of study subjects such as male sex, but also by modifiable factors including alcohol abuse and distal pancreatectomy.