The evaluation of hepatic fibrosis on histological sections is of great interest for the staging and follow-up of chronic liver disease. Because no reliable scoring system is yet available, we have designed a semiquantitative scoring system in which the four main sites of fibrotic deposit--centrilobular vein, portal tract and perisinusoidal space, together with width and number of septa when present--are analyzed. These different items have been previously settled from comparison with morphometric measurements to evaluate surface density of total collagen performed on the same liver needle biopsy specimens stained with picro-sirius. The score has been tested on samples from 200 consecutive patients with various liver diseases and compared with the surface density of total collagen and Knodell scoring system. For observer variation study, the features by three independent pathologists were coded on 20 cases. There was a good interobserver (Kendall's tau-b = 0.75) and intraobserver (tau-B = 0.73) reproducibility. Each component of the fibrosis scoring system and total collagen surface density were significantly linearly related (one-way polynomial analysis, p < 10(-4); the correlation between semiquantitative scoring system and surface density of total collagen was 0.73 (p < 10(-5). Our semiquantitative scoring system, simple and reproducible, describes both liver architecture and fibrotic deposit. It is better related to morphometric measurement of fibrosis than each of its constituents or than the fibrosis item of the Knodell scoring system. It represents a reliable and convenient method for fibrosis evaluation, which is mandatory for clinical use.