Objective To investigate the characteristics and clinical significance of peripheral blood dendritic cell (DC) subsets in patients with primary hepatocellular carcinoma (HCC). Methods Twenty-six HCC patients were enrolled for study. Twenty three patients with chronic HBV infection and twenty healthy individuals were entered as controls. Peripheral blood DC subsets and lymphocyte subsets of patients and healthy subjects were analyzed by flow cytometry. Interferon-?(IFN-?) production of peripheral blood mononuclear cells (PBMC) induced by inactivated herpes simplex virus type 1 (HSV-1) was measured by a human IFN-? ELISA kit. Results Compared with healthy subjects, patients with HCC had a significantly decreased proportion and absolute number of DC1 and DC2 (P