The nm23-H1 gene product has been considered as an anti-metastatic protein and the level of its expression has been reported to correlate inversely with metastatic potential in some cancers. However, the expression of nm23-H1 gene product in the metastatic sites have not been studied in detail. We examined the expression of nm23-H1 gene product in surgically resected 46 pairs of primary lung cancers and metastatic lymph nodes by immunohistochemistry. The positive staining of nm23-H1 gene product in primary cancers and metastatic lymph nodes were observed in 56.5 and 67.4%, respectively. The heterogeneity of nm23-H1 gene product expression between primary cancers and metastatic lymph nodes was observed in 41.3%. No correlations were found between the nm23-H1 gene product expression in lung cancers and the patients survival. No significant association was also observed between nm23-H1 gene product expression in lymph nodes and the patients survival. There was, furthermore, no correlation between the heterogeneity of nm23-H1 gene product expression and the patients survival. In conclusion, the level of nm23-H1 gene product expression does not significantly reveal prognostic value in node-positive lung cancers. Expression of nm23-H1 gene product in metastatic lymph nodes was also unrelated to patients survival.