PURPOSE: The CD44 has been known a lymph node homing receptor on circulating lymphocytes. CD44 spliced variants have been found to be overexpressed in human cancers and metastatic cancers. The variant CD44v 6-7 in particular has been suggested to have a potential role in tumor metastasis. It has been reported that histopathological examination could occaisionally miss lymph node micrometastasis. PURPOSE: The aim of this study was to investigate the role of CD44v in metastasis of rectal carcinoma to the pelvic lateral lymph nodes around the obturator nerve, obturator vessel and superior vesical artery. METHODS: Thirty pelvic lateral lymph nodes reported normal histopathologically from 22 patients with rectal carcinomas, 22 rectal carcinomas and their corresponding colonic mucosas. We have used RT-PCR for the detection of CD44 gene products (CD44v and CD44 v6-7) in samples. RESULTS: The expression rates of CD44v were 2/22 (9%) for normal colonic mucosa, 20/22 (90%) for cancer tissues, and 4/30 (13.3%) for pelvic lateral lymph nodes. The rates of CD44v6-7 were also 2/22 (9%) for normal colonic mucosa 20/22 (90%) for cancer tissues, but 7/30 (23.3%) for pelvic lateral lymph nodes. CONCLUSIONS: The analysis of CD44v might be useful for determination of pelvic lateral lymph nodes metastasis, but it should not be used as a metastatic marker in general for rectal cancer patients.