Serum antineutrophil cytoplasmic antibodies (ANCAs) are a sensitive and specific marker for generalized Wegener's granulomatosis. However, ANCA sensitivity and specificity in identifying patients in whom ophthalmic signs constitute the presenting or only definitive manifestation of Wegener's granulomatosis have not been tested. The authors report on 7 patients in whom scleritis was the initial manifestation leading to the diagnosis of Wegener's granulomatosis. Six had the limited form of Wegener's granulomatosis. Results of serum ANCA tests were positive in all these patients. In contrast, the serum ANCA was negative in 54 patients with ocular inflammation due to other disorders; 16 of these patients had scleritis. Serial ANCA titers reverted to normal in only two of the four patients with Wegener's granulomatosis who attained clinical remission. One of the patients who did not revert to normal experienced relapse 2 months after discontinuation of therapy. Antineutrophil cytoplasmic antibodies appear to be both sensitive and specific for Wegener's granulomatosis-associated scleritis, and testing is useful in the evaluation of patients with scleritis.