Background/AIM: Interleukin-8 (IL-8) is known as a chemotactic and angiogenetic cytokine and is a potential mediator of host response to injury or inflammation. In order to identify the role of IL-8 in the pathogenesis of chronic hepatitis C (CHC), we assessed semiquantitatively the messenger RNA (mRNA) expression of IL-8 and other cytokines in liver biopsy specimens of CHC patients. METHOD: Liver biopsy specimens were obtained under peritoneoscopy from 35 patients with CHC. The mRNA expression of IL-8 and other cytokines in the liver were determined by real-time PCR and the correlation between the mRNA expression and histological classification of liver were studied. Liver histology was classified by both staging of fibrosis (F0-F4) and grading of activity (A1, mild; A2, moderate and A3, severe). RESULTS: Patients were classified into F1, 8; F2, 9; F3, 9 and F4, 9 and A1, 6; A2, 14 and A3, 15, by staging of fibrosis and grading of activity, respectively. Expression of IL-8 mRNA increased with staging of fibrosis (F1, 0.402+/-0.65; F2, 0.413+/-0.246; F3, 1.388+/-2.166; F4, 1.991+/-1.879) and grading of activity (A1, 0.560+/-0.808; A2, 0.780+/-1.268; A3, 1.548+/-1.957). The mRNA expressions of IL-2, IL-1alpha, IL-1beta, IL-15 and TNF-alpha were found to be closely correlated with IL-8 mRNA (R=0.638; 0.522; 0.487; 0.465 and 0.495, respectively, in all P<0.05). CONCLUSION: In CHC, intra-hepatic expression of both IL-8 and IL-2 increased with fibrosis and inflammatory activity. Positive correlations were found between IL-8 and other cytokines and between cytokines themselves. These findings suggest that these interacting cytokines play an active role in the pathogenesis of CHC, and maybe involved in the upregulation or induction of one and other.