In order to investigate the expression levels of Pin1 mRNA and protein in cervical cancer and its association with Ki67 and their clinical significance, amplification of Pin1 gene was examined by RT-PCR, and the expression of both Pin1 and Ki67 protein was detected by immunohistochemistry in cervical cancer tissues. It was shown that the expression levels of Pin1 were higher in cervical cancer than in normal cervical tissues (P < 0.05). The expression of Pin1 protein was increased progressively along with the disease process from normal cervix to CIN and to cervical cancer (P < 0.05). No significant difference in the Pin1 expression was found between disease stages (FIGO), pathological grades or pelvic lymph node metastasis status (P > 0.05). The expression of Pin1 was significantly higher in adenocarcinoma than in squamous carcinoma of the uterine cervix (P < 0.05). In cervical cancer, the overexpression of Pin1 was positively correlated with that of Ki67 (P < 0.05). These results suggested that the overexpression of Pin1 was closely related with cancer cell proliferation or progression of cervical cancer and contributed to oncogenesis. Pin1 may serve as a potential marker for cervical cancer diagnosis.