Aberrant transcription of the FHIT gene has been observed in many solid tumors, suggesting that 5'-CpG island methylation of the FHIT gene is involved in tumor development. The authors investigated the status of the 5'-CpG island methylation of the FHIT gene and protein expression in a series of 40 cervical carcinomas and 10 normal cervical epithelial samples, and correlated the data with clinicopathological findings. Methylation-specific PCR was applied to detect the incidence of the 5'-CpG island methylation, and immunohistochemistry was used for FHIT protein staining. 5'-CpG island methylation of the FHIT gene was detected in 40% (16/40) of the cervical cancer samples and in none of normal cervical epithelial specimens. Furthermore, the 5'-CpG island methylation was positively associated with clinical stage (p=.002). All the normal cervical epithelial samples (10/10) and 90% (36/40) of the cervical carcinomas were positive when the unmethylated primer pair was applied. Of the 16 cervical carcinomas with 5'-CpG island methylation of the FHIT gene by PCR, 15 showed reduced FHIT protein expression. This study suggests that 5'-CpG island methylation plays an important role in inactivation of the FHIT gene in cervical cancer.