['Although peritoneal washing cytology has been widely used in the field of gynecology, it has not been performed so frequently in patients with pancreatic cancer. Only a few papers have reported surgical implications of peritoneal washing cytology.', 'We reviewed results of peritoneal washing cytology performed immediately after laparotomy in 50 Japanese patients with pancreatic cancer. The 50 patients were divided into two groups according to the results of cytology. Clinicopathological findings were compared between these two groups.', 'Cytology of peritoneal washing was positive in 13 (26%) of the 50 patients. Nine of the 13 patients had no visible peritoneal dissemination. There were no significant differences regarding the age, tumor size and serum level of the carcinoembryonic antigen. Moderately to poorly differentiated adenocarcinoma and perineural invasion (ne3) and lymphatic permeation (ly3) of marked degree were more frequent in the positive group than in the negative group (p < 0.01). The survival curve of the 37 patients with negative cytology was significantly better than that of the 13 with positive cytology (p < 0.01). Four of 13 patients with positive cytology underwent a potentially curative resection but died within 12 months. Three of these four patients died of peritonitis carcinomatosa with massive malignant ascites and one died of local recurrence.'] Does positive washing cytology in patients with pancreatic cancer indicate a contraindication of pancreatectomy?