The serum levels of hepatocyte growth factor (HGF) were determined in chronic renal failure (CRF) patients. Nondialysis patients with renal insufficiency had significantly higher serum HGF than normal subjects (0.34 ± 0.10 ng/ml, n = 21 vs. 0.19 ± 0.05 ng/ml, n= 15; p < 0.001), and the elevated serum HGF correlated with their serum creatinine levels. Hemodialysis (HD) patients treated for 5-10 years showed higher serum HGF than those receiving HD for 1 year or less (0.45 ± 0.14ng/ml, n = 8vs. 0.33 ± 0.11ng/ml, n = 9; p < 0.05). Continuous ambulatory peritoneal dialysis patients also showed elevated serum HGF levels comparable to those of HD patients. There was no difference in serum HGF levels in HD patients with or without acquired cystic disease of kidney. Consequently, serum HGF is elevated in CRF, which may be attributed to the increased production of HGF in response to the chronic renal injury, the effect of heparin, or reduced removal of serum HGF in CRF patients.