Over the past 20 years, remarkable progress has been made in understanding the pathogenesis and treatment of patients with small vessel vasculitis. Nephrologists and rheumatologists play primary roles in the care of these patients. Whilst there are many areas of agreement between these specialists with respect to understanding and practical care of these patients, there are a number of important areas that differ in the practice patterns of nephrologic and rheumatologic practice. These areas include the nomenclature of these diseases, the role of antineutrophil cytoplasmic antibodies in the pathogenesis, the route and duration of initial cyclophosphamide administration, and, most importantly, the total duration of maintenance therapy following disease remission. Two experienced clinicians, a rheumatologist and a nephrologist, spar off in support of their opinions.