This study aimed at characterizing the levels of CCL20 mRNA transcripts in peripheral mononuclear blood cells (PMBC) of 56 Chinese patients with inflammatory bowel disease (IBD), 30 other intestinal diseases and 30 healthy controls by quantitative real time polymerase chain reaction. The levels of CCL20 mRNA transcripts in PBMC of patients with IBD were significantly higher than that of patients with non-IBD intestinal diseases and healthy controls (p < 0.01) and the CCL20 expression in active IBD patients was significantly higher than that in remission patients (p < 0.01). Importantly, the levels of CCL20 expression in PBMC were significantly correlated with the degrees of disease severity, the levels of erythrocyte sedimentation rate and C-reaction protein, but not hemoglobin, in patients with IBD (p < 0.01). Furthermore, the levels of CCL20 expression in active IBD patients after treatment with salazosulphapyridine or prednisone were significantly reduced, as compared with before treatment (p < 0.01). Therefore, analysis of CCL20 expression in PBMC may be used as a surrogate measure for evaluation of IBD activity, disease progression and therapeutic efficacy in Chinese IBD patients.