There is a lack of data in France on the number of patients diagnosed with chronic hepatitis C (HCV) and on the morbidity associated with this condition. To estimate the population of patients with chronic hepatitis C who sought medical care in France between 1991 and 1994, a study was conducted using a random sample of healthcare facilities authorized to prescribe interferon alpha. The results of this study, compared with the estimated number of HCV-positive individuals (500,000 to 650,000), suggest that only a small proportion (5%) of these individuals are currently diagnosed and managed in specialized care settings.