Two known di-allelic polymorphisms in the tumor necrosis factor (TNF) genes were investigated in 35 patients suffering from Wegener's granulomatosis (WG) in comparison to 111 healthy controls. The first polymorphism lay in the promotor region of the TNF-alpha gene at position -308, the second in the first intron of the TNF-beta gene. For both polymorphisms we could not find any statistically significant differences in allele frequencies between patients and healthy individuals. In the patient group the TNF 2/2 phenotype was slightly elevated, however (WG 5.7% vs. normal 1.8%). Investigating the clinical course of the disease according to TNF polymorphisms, TNF 1/1 patients were found to have a higher mean disease extension index (DEI) than TNF 1/2 individuals (TNF 1/1 10.5 vs. TNF 1/2 9.4).