Background/Aims: CD44 is a cell surface molecule which is divided into CD44s and CD44v subsets. The relationship between th expressions of CD44 variant and progression of colorectal carcinoma has not been defined. The aims of this study were to analyze the expressions of CD44s and CD44v6 in colorectal adenoma and colorectal carcinoma by immunohistochemical methods and to evaluate the relationship between their expressions and various clinicopathological prognostic factors. Methods: We evaluated retrospectively the records of 20 cases of colorectal adenoma and 56 cases of colorectal carcinoma. The expressions of CD44s and CD44v6 were investigated by immunohistochemical staining. Results: CD44s was expressed in all cases of adenoma and in 86% of colorectal carcinoma (p>0.05). The expression rates of CD44v6 were 20% in colorectal adenoma and 80% in colorectal carcinoma (p<0.01). In colorectal carcinoma, the expression of CD44s showed no significant relationship with various prognostic factors, but the expression rate of CD44v6 was significantly increased according to histologic grade. There was no significant difference in the expression rate of CD44v6 according to the stage of the disease and tumor invasion. Conclusions: In colorectal carcinoma, CD44v6 expression was significantly increased in relation with histologic grade and lymph node metastasis. These results suggested that CD44v6 could be useful as a marker of tumor progression and metastasis, but further study is needed.