Intrahepatic cholangiocarcinoma (ICC) is a fatal, malignant tumor of the liver; effective diagnostic biomarkers and therapeutic targets for ICC have not been identified yet. High expression of H2A histone family member Z (H2A.Z) is a high-risk factor for poor prognosis in patients with breast cancer and primary hepatocellular cancer. However, the significance of H2A.Z and its expression in ICC remains unknown. The present study demonstrated that H2A.Z is overexpressed in ICC and expression of H2A.Z correlated with poor prognosis in patients with ICC. H2A.Z regulated cell proliferation in vitro and in vivo via H2A.Z/S-phase kinase-associated protein 2/p27/p21 signaling. Inhibition of H2A.Z reduced cell proliferation and induced apoptosis in ICC. In addition, downregulation of H2AZ reduced tumor metastasis by repressing epithelial-mesenchymal transition and enhanced the antitumor effects of cisplatin in the treatment of ICC. Overall, H2A.Z promoted cell proliferation and epithelial-mesenchymal transition in ICC, suggesting that H2A.Z may be a novel biomarker and therapeutic target for ICC.