Cyclin D1 and E have been found to be deregulated and overexpressed in various types of cancers. In order to study the cell cycle regulatory mechanisms in gastric cancer, we have analyzed the protein expression of cyclin D1 and cyclin E in 76 tumor specimens from patients with primary gastric cancer, using immunohistochemistry. Overexpression of cyclin D1 was observed in 38 cases (50.0%). Overexpression of cyclin E was observed in 40 cases (52.6%). There was no significant difference between the expression of cyclin D1 and any clinicopathological factor. Cyclin E overexpression was correlated with a high incidence of lymph node metastasis, a low incidence of T1, and with Stage I. There was no significant difference in survival curves between cyclin D1 (+) and cyclin D1 (-). The survival curves of cyclin E (-) were significantly higher than those of cyclin E (+). These results suggested that in gastric carcinoma, cyclin E overexpression was useful as a prognostic indicator, but cyclin D1 was not.