Sequential low-dose Methotrexate.5FU therapy was conducted on a total 52 cases of advanced or recurrent gastric carcinoma. Intra-aortic infusion therapy was performed in 31 cases and intravenous administrative therapy was employed in the remaining 21 cases. The two groups were compared in terms of the response rate and side effects. Thirty mg/m2 of Methotrexate (MTX) was given by bolus injection into the aorta or venous route, followed by 500 mg or 750 mg of 5FU by bolus injection 3 hours later. Twenty four hours after the injection of MTX, 30 mg of Leucovorin was given intravenously or orally. The major lesion of intra-aortic infusion group was primary site (stomach) in 10 cases, peritoneum and digestive tract in 9 cases, Douglas' pouch in 5 cases, liver in 3 cases, abdominal wall in 2 cases and retro-peritoneal lymph nodes in 2 cases. On the other hand, the major lesion of the intravenous administrative group was the primary site (stomach) in 5 cases, peritoneum and digestive tract in 6 cases, Virchow's lymph-node in one, hepatic hilus in one and lung in one. Response could be evaluated in 31 patients with intra-aortic therapy. Partial response was found in 9 cases and NC in 16. PD was found in 5 and so the rate of response was 29.0% (9/31). The major lesion of 9 responders was inoperable Borrmann's Type 4 gastric cancer in 2 cases, peritoneal recurrence with an abdominal mass in 4, recurrence in the abdominal wall in one, Douglas' pouch in one, and intestinal stenosis in one.(ABSTRACT TRUNCATED AT 250 WORDS)