Obejctive To evaluate the diagnostic value of PET/CT in the diagnosis of liver metastases by meta-analysis. Methods We searched databases including CNKI, CBM, VIP, WanFang Data, PubMed, EMbase, web of science and The Cochrane Library until April 2017 to collect studies about PET/CT in the diagnosis of liver metastases. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data, and assessed the risk of bias of included studies by using the QUADAS-2 tool. Then, meta-analysis was performed by using Stata 12.0 software. Results A total of 15 studies from nine countries were included, involving 1628 patients and 1022 nodules. The results of meta-analysis showed that, the pooled sensitivity, specificity and area under SROC curve of PET/CT for diagnosing liver metastases were:a)on per-patient based, 0.95(95%CI 0.92-0.97), 0.94(95%CI 0.87-0.97) 0.98(95%CI 0.97-0.99); b) on perlesion based, 0.82(95%CI 0.61-0.93), 0.95 (95%CI 0.89-0.98), 0.97(95%CI 0.95-0.98). The results of subgroup analysis showed that no significant differences of AUC were found among all subgroups (P＞0.05). Conclusion PET/CT has a good diagnosis value for liver metastases which can be used as an noninvasion tool for suspected patients with liver metastases, especially on per-patient based.