To evaluate the significance of nm23 protein expression in cervical carcinoma, 83 patients with stage IB disease, treated primarily with surgery were studied immunohistochemically. Of the cases 57 were squamous carcinoma, 9 were adenocarcinoma, 14 were adenosquamous carcinoma and 3 were small-cell carcinoma. nm23 expression was positive in 63% of the cases. Although positive expression was more common in squamous and adenosquamous type tumors, negative expression was dominant in adenocarcinoma (P<0.05). When nm23 expression was compared with the clinicopathologic risk factors, there was no correlation of expression with the grade, deep invasion of the stroma, parametrial involvement and lymph node metastasis. But expression was inversely correlated with the number of metastatic lymph nodes (P<0.05). Although 3 or more lymph node metastases is a very poor prognostic sign, nm23 expression was not correlated either with recurrence or survival. Expression was negative in 77% of metastatic lymph nodes and in all of the recurrences. The predominance of negative expression in metastatic lymph nodes (P<0.05) and recurrences seems to be related to the aggressive behavior of the negative clone in the heterogeneous primary tumor.