Estimates of the extent of hepatic fibrosis and the rate of fibrosis progression represent important surrogate end points for evaluation of the vulnerability of an individual patient and for assessment of the impact of treatment on natural history in chronic hepatitis C. Using the median fibrosis progression rate, the median expected time to cirrhosis in untreated patients is around 30 years. However, one third of patients have an expected median time to cirrhosis of less than 20 years and one third will only progress to cirrhosis in more than 50 years, if ever. Factors independently associated with fibrosis progression are duration of infection, age, male gender, consumption of alcohol, human immunodeficiency virus co-infection, and low CD4 count. Evaluation of fibrosis progression is useful to decide treatment. Among patients with sustained viral response, fibrosis regresses. Evaluation of fibrosis progression has permitted validation of the concept of suppressive therapy. Among patients without viral clearance, interferon alone or in combination with ribavirin significantly reduces fibrosis progression rate in comparison with progression before treatment and to control groups. There is a major need for noninvasive markers of liver fibrosis. None are clearly useful today for the diagnosis of early stages of fibrosis.