approximately 80 % of hepatitis c evolves to chronicity. the epidemiological and viral factors as well as those of the guest take part in the progression of the disease. the behavior of the epidemiological variables associated with chronic hepatitis c was described and the possible association of these ones with the intensity of fibrosis was identified. 80 patients with hepatitis c were studied and the intensity of fibrosis was determined by the metavir scoring system. they were grouped into absence or little fibrosis (f0-f1) and marked fibrosis (f2-f4) seeking for the possible statistical association with the epidemiological factors. a significant association was found among the infection's oldness estimate, the way it was acquired, the patient's age on catching it and the intensity of fibrosis. the progression of hepatits c may be determined by some epidemiological factors influencing decisively the natural history of the disease.