In a retrospective series of 445 gastric cancer patients, the prognostic significance of classical histological parameters such as T-category, tumor size, lymphnode involvement and tumor grading was compared with the prognostic value of vascular invasion and the degree of tumor cell dissociation (TCD) at the invasion front. As shown in a Cox regression analysis, T-category had the highest prognostic value. Nevertheless, vascular invasion and TCD proved to be independent new parameters in a multivariate analysis, exceeding the prognostic information obtained by the combination of T-category and lymph-node involvement. In contrast, tumor grading provided no significant information. The determination of TCD at the invasion front as well as a careful search for vascular invasion may therefore provide additional useful information for identifying those patients who are at high risk and who may be candidates for adjuvant therapy in future clinical trials.