Tumor necrosis factor alpha (TNF-alpha) and basic fibroblast growth factor (bFGF) have been assigned a major role in the induction of angiogenesis. By performing immunohistochemical studies of cauterized mouse corneas, the in situ distribution of bFGF and TNF-alpha in the course of inflammatory neovascularization was investigated. bFGF was found throughout the corneal epithelium of untreated and cauterized eyes. However it was only rarely detected in the endothelium or in infiltrating cells before the onset of neovascularization. TNF-alpha was not expressed by any cell before the ingrowth of new blood vessels, which took place within 36 hours after cauterization. It is concluded that the release of these cytokines by infiltrating cells is of minor or no importance for the induction of sterile inflammatory angiogenesis.