Univariate and multivariate analyses of possible prognostic factors were carried out on data from 142 patients who had undergone curative resection for a carcinoma of the stomach invading beyond the muscularis propria. In the univariate analysis, factors including age, size of cancer, gross form, depth of penetration, lymph node metastasis, lymphatic invasion, width of serosal invasion, mode of invasion, volumetric shape of invasion, and stage had an individual prognostic significance. The multivariate analyses indicated that stage, lymph node metastasis, and depth of penetration were the most significant prognostic factors and that the prognosis in cases of obvious serosal invasion, or those with secondary or tertiary nodal involvement, was poor. For such patients, we prescribe postoperative intensive chemotherapy, even when a "curative" operation is done.