Despite improved overall prognosis of patients with ANCA-associated vasculitis (AAV), those presenting with impaired renal function remain at risk of developing end-stage renal disease (ESRD). In addition to its role in diagnosis, renal histology provides prognostic information that has permitted definition of subgroups with differing risks of ESRD. In this issue, Brix et al. have developed and validated a risk score to predict the probability of ESRD. Against a background of outcome prediction in AAV, this commentary assesses different approaches to histologic risk and to what extent they assist with decisions on patient management.