The authors report a case of cystic neoplasm of the pancreas treated by cystojejunostomy two years and half earlier. On that occasion, a false diagnosis of pancreatic pseudocyst had been suggested. Cystic neoplasm of the pancreas has a far better prognosis than adenocarcinoma. However, early detection is difficult and erroneous initial diagnosis may lead to delayed treatment and poor long-term results. In our case, though surgical treatment was aggressive and apparently radical, early recurrence of neoplasm was observed. Only early accurate diagnosis of pancreatic cystadenocarcinoma might improve the results of surgical treatment.