• Although eosinophils and neutrophils have been identified in orbital and corneoscleral tissues in some patients with Wegener's granulomatosis, their role in the pathogenesis of the disorder is not completely understood. Nine specimens from six patients with Wegener's granulomatosis and autopsy controls from patients without ophthalmic disease were evaluated with indirect immunofluorescence for eosinophil granule major basic protein and neutrophil elastase. Extracellular deposition of both major basic protein and elastase was identified in orbital tissues from all the patients with Wegener's granulomatosis. Two of the specimens were from enucleated eyes with corneoscleral disease; extracellular deposition of eosinophil major basic protein was identified in one eye, and extracellular neutrophil elastase was deposited in both eyes in lesional areas. None of the control tissues showed major basic protein or elastase deposition. These findings suggest that both eosinophils and neutrophils participate in the pathogenesis of the orbital and corneoscleral manifestations of Wegener's granulomatosis.