Thirty-seven patients (21 female, 16 male) with Wegener's granulomatosis (WG) were reviewed. Patients were followed for a mean six years after diagnosis; 14 were followed for more than seven years. The clinical features were similar to those in previous studies. In this series, only 13 patients (35%) had renal disease at presentation and the cumulative incidence of renal involvement was 51%. Thirty-one patients received treatment which included cyclophosphamide (CP). The case fatality rate of the six patients not treated with CP was 83% (five deaths). By contrast, all CP treated patients improved and 21 (68%) had complete remissions. Nine (29%) were in complete remission for a mean 4.9 years after discontinuing all treatment. Two were disease free for over ten years. The actuarial probability of survival for these patients was 97% at one year and 71% at ten years. Only three CP treated patients (10%) progressed to end-stage renal disease. The case fatality rate was 26% (eight patients) and sepsis was the cause of death in five. Fourteen patients (45%) treated with CP had at least one relapse of vasculitis and seven (23%) had multiple (two or more) relapses. These data indicate that CP is effective in inducing remissions and prolonging survival in patients with WG; however, relapses are frequent.