For 3 years beginning in 1984, 14 advanced and recurrent gastric cancer cases with measurable lesions (8 unresected cases, 3 cases of recurrence, 2 cases with non-curative resection, 1 case of no operation) were treated by CDDP therapy alone or in combination with other chemotherapies. CR was obtained in 2 of the 8 non-resected cases, radical gastrectomy being feasible in these 2 cases by second-look operation. Five of the 8 cases showed PD, and in 1 case the effect was rather obscure. One of the 2 non-curative resection cases achieved PR, and the other case was MR. One of the 3 recurrent cases was NC, the remaining cases being PD. The one case given no operation showed PD. Overall effectiveness of CDDP therapy for advanced and recurrent gastric cancer cases was seen in 3 (21.4%) of the 14 cases. All of these 3 cases showing effective CDDP therapy was elevated serum CEA values before the therapy, which was markedly reduced after starting the therapy, the reduction rate being very remarkable.