The purpose of this study is to assess the efficacy and safety of a staged treatment regimen in Wegener's granulomatosis and related vasculitides in which patients will receive glucocorticoid plus cyclophosphamide at disease onset; cyclophosphamide will be switched to methotrexate upon disease remission. At the current time, cyclophosphamide plus glucocorticoids are the standard of care for the treatment of these disorders. Although this regimen has brought about a marked improvement in survival rate, it has been associated with significant toxicity. Methotrexate plus glucocorticoids have recently been investigated in patients with non life-threatening disease and while this regimen appears to have less toxicity than standard therapy it may be associated with a higher rate of disease relapse. By inducing patients with cyclophosphamide and glucocorticoids then switching to methotrexate at remission, we hope to combine the efficacy of cyclophosphamide with the more favorable toxicity profile of methotrexate. If successful, this regimen could provide a safer, yet effective therapeutic option which would be applicable to all patients regardless of disease severity. In this study, patients will be initially treated with cyclophosphamide and glucocorticoids and then switched from cyclophosphamide to methotrexate upon quiescence of disease activity. If at the end of two full years of methotrexate therapy there is continued evidence of disease remission, the drug will be tapered and ultimately discontinued. Patients will be prospectively monitored for evidence of disease activity and drug toxicity. Specific parameters that will be obtained include the time to disease remission, the rate and time of disease relapse, and the incidence of drug related adverse effects. This study will be open to patients with systemically active Wegener's granulomatosis or related vasculitis regardless of their degree of disease severity.