Protein-energy malnutrition is a notable problem in the management of patients with chronic pancreatitis. The effect of malnutrition on pancreatic surgery is not well known. The records of 313 consecutive patients who underwent lateral pancreaticojejunostomy (LPJ, n = 152), pancreaticoduodenectomy (PD, n = 78), or distal pancreatectomy (DP, n = 83) for chronic pancreatitis were retrospectively reviewed and analyzed. Subjective Global Assessment, Nutritional Risk Index, and Instant Nutritional Assessment were used to assess the nutritional state. An average of all three nutritional indexes was established, and patients were categorized into well nourished (n = 101) as well as mild (n = 91), moderate (n = 94), and severe malnourished (n = 27). Poor nutritional state was associated with an increase in postoperative complication rate (LPJ: well nourished 14%, mild 25%, moderate 31%*, severe 50%*; PD: well nourished 44%, mild 44%, moderate 60%, severe 88%*; DP: well nourished 17%, mild 13%, moderate 30%, severe 55%*; *P < 0.045 vs well nourished). Low serum albumin levels also increased operative morbidity. The increase in morbidity was reflected by a higher rate of infectious complications as well as increased ICU stay. Body mass index and weight loss did not contribute to change in outcome. Malnutrition was associated with a higher incidence of postoperative complications after surgery for chronic pancreatitis. An increase in operative morbidity might be related to decreased protein synthesis and impaired immunocompetence.