Forty-nine consecutive patients with advanced gastric carcinoma underwent preoperative staging by laparoscopy between June 1991 and June 1992. Peritoneal lavage with cytologic examination was performed when ascites was not present. In eight cases (16.3%), laparoscopy revealed carcinomatosis and/or multiple hepatic metastases, so laparotomy was not performed. Intraperitoneal free cancer cells (IFCCs) were detected in 41% of patients (65% in patients with ascites and 28% by peritoneal lavage). In the absence of macroscopic peritoneal dissemination, IFCCs were encountered in 29% of patients. IFCCs were present only when invasion of the gastric serosa was >3 cm2 or when adjacent organs and structures were already invaded. Mucinous adenocarcinoma, Borrmann class IV tumors, and Stage IV patients had higher incidence of IFCCs. Cytologic results were similar at laparoscopy and laparotomy (p > 0.05). Therefore, cytologic evaluation of peritoneal lavage added sensitivity to laparoscopy in assessing patients with advanced gastric carcinoma and may alter their therapeutic approach.