Aberrant expression of the cell adhesion molecule CD44 has been detected in human tumours and has been shown to be associated with metastasis and poor prognosis in human malignancies. We evaluated serum levels of different soluble CD44 molecules (CD44 standard form and CD44 splice variants v5 and v6) in cervical cancer patients stage IB to IIIB. Two-hundred three serum samples were analysed. Serum levels of CD44st and CD44v5 showed no significant correlation with the presence or absence of cervical cancer. The splice variant CD44v6 showed a mean concentration of 227.3 +/- 90.9 (minimum 71.4, maximum 543.9) ng/ml when tumour was present and a mean concentration of 198.7 +/- 135.4 (minimum 67.2, maximum 696.3) ng/ml in cases of complete remission (P-value = 0.0001). However, in this preliminary study the sensitivity/specificity characteristic of CD44v6 was poor.