Type IV collagen, one of the serum markers for hepatic fibrosis, was measured perioperatively in patients with and without chronic liver damage to investigate whether this parameter changes in response to acute stress to the liver and can predict the surgical risk of hepatic resection. The serum type IV collagen level was significantly elevated in patients with liver cirrhosis. There were significant correlations between serum type IV collagen levels and the indocyanine green clearance test and cholinesterase activity, although the correlation coefficients were not high. The size of the resected hepatic mass was not the primary factor to influence the postoperative serum type IV collagen level. In patients with liver cirrhosis, the postoperative serum type IV collagen level increased significantly compared to that in patients with normal liver or chronic hepatitis. Postoperative liver failure occurred in 0%, 11.6%, and 44.4% of patients with preoperative serum type IV collagen levels of <150, < or = 150 to 300, and > or = 300 ng/ml, respectively. In those with postoperative liver failure, the serum type IV collagen levels were significantly higher both pre- and postoperatively compared to those in patients with uneventful courses. Several preoperative liver function tests indicated that type IV collagen is an independent risk factor for postoperative liver failure. Thus perioperative measurement of the serum type IV collagen levels seemed to be useful for predicting the risk of hepatic resection in patients with chronic liver damage.