Context: Endocrine and exocrine insufficiency after partial pancreatectomy affect quality of life, cardiovascular health, and nutritional status. However, their incidence and predictors are unknown. Objective: To identify the incidence and predictors of new-onset diabetes and exocrine insufficiency after partial pancreatectomy. Design: We retrospectively reviewed 1165 cases of partial pancreatectomy, performed from 1998 to 2010, from a large population-based database. Main Outcome Measures: Incidence of new onset diabetes and exocrine insufficiency. Results: Of 1165 patients undergoing partial pancreatectomy, 41.8% had preexisting diabetes. In the remaining 678 patients, at a median 3.6 months, diabetes developed in 274 (40.4%) and pancreatic insufficiency developed in 235 (34.7%) patients. Independent predictors of new-onset diabetes were higher Charlson Comorbidity Index (CCI; hazard ratio [HR] = 1.62 for CCI of 1, p = 0.02; HR = 1.95 for CCI ≥ 2, p < 0.01) and pancreatitis (HR = 1.51, p = 0.03). There was no difference in diabetes after Whipple procedure vs distal pancreatic resections, or malignant vs benign pathologic findings. Independent predictors of exocrine insufficiency were female sex (HR = 1.32, p = 0.002) and higher CCI (HR = 1.85 for CCI of 1, p < 0.01; HR = 2.05 for CCI ≥ 2, p < 0.01). Distal resection and Asian race predicted decreased exocrine insufficiency (HR = 0.35, p < 0.01; HR = 0.54, p < 0.01, respectively). Conclusion: In a large population-based database, the rates of postpancreatectomy endocrine and exocrine insufficiency were 40% and 35%, respectively. These data are critical for informing patients’ and physicians’ expectations. [ABSTRACT FROM AUTHOR]