Objective To study the interaction between telomerase activity and abnormalities of the p16 gene in liver metastases of colorectal carcinoma. Methods Telomerase activity was detected by a non-isotopic PCR-based telomeric repeat amplification protocol (TRAP) assay, and homozygous deletions of the p16 gene were detected by a semiquantitative multiplex polymerase chain reaction in tissue samples from 24 liver metastases of colorectal carcinoma and 5 primary colorectal carcinomas. Results Telomerase activity was observed in 19 (79.2%) of 24 liver metastases of colorectal carcinoma. Telomerase activity was also observed in all 5 primary colorectal carcinomas and in 3 of their liver metastatic samples. The incidence of telomerase activity in liver metastases of colorectal carcinoma was not significantly correlated to tumor diameter, number of tumors, cirrhosis, and HBsAg. Homozygous deletions of the p16 gene were found in 9 of 24 (37.5%) liver metastases of colorectal carcinoma. Homozygous deletions of the p16 gene were observed in 2 of the 5 primary colorectal carcinomas and in 1 of the matching liver metastatic cancers. There was a correlation between telomerase activity and homozygous deletions of the p16 gene. Conclusions There is a correlation between telomerase activity and homozygous deletions of the p16 gene in liver metastases of colorectal carcinoma, suggesting its crucial role in liver metastases. However, telomerase activation and homozygous deletions of the p16 gene might not be the initiating event in liver metastases of colorectal carcinoma.