Background Peritoneal carcinomatosis is common after curative resection of gastric cancer. Intraperitoneal administration of paclitaxel (PTX) is known to control ovarian peritoneal metastases. Patients and methods Patients with either linitis plastica or T4 cancer with high risk of peritoneal metastasis or recurrence but whose cancer was considered resectable were preregistered. After their cancer had been confirmed intraoperatively as resectable, the patients were randomized into either group A (PTX at 60 mg/m 2 intraperitoneally on the day of surgery and on days 14, 21, 28, 42, 49, and 56) or group B (PTX at 80 mg/m 2 administered intravenously by the identical schedule) before being treated by evidence-based chemotherapy. The primary end point was the 2-year survival rate. Safety, the secondary end point, was also analyzed. The study has been registered as UMIN000002957. Results Of 177 preregistered patients, 83 underwent treatment (39 by intraperitoneal administration and 44 by intravenous administration). There was no difference in patient demographics between the two groups. The incidences of surgical complications were similar between the groups, except for transient bowel obstruction observed exclusively in group A. The relative dose intensity of PTX was 81.4 % for group A and 76.3 % for group B. There was one death due to pulmonary thrombosis and a case of anaphylaxis that led to termination of the protocol treatment (group B). Other adverse events were mild and manageable. Conclusions Intraperitoneal administration of PTX from the day of gastrectomy did not result in a higher incidence of surgical complications and adverse reactions when compared with intravenous administration of PTX.