The new Oxford Classification of the Pathology of IgA nephropathy originated from an international collaborative effort of the Working Group of the International IgA Nephropathy Network and Renal Pathology Society. It provides a new common language to categorizing glomerular and tubulo-interstitial lesions in IgA nephropathy having a proved effect on progression. Although retrospective in design and requiring future prospective validation, the Oxford collaboration defined and scored four pathologic parameters having an influence on outcome (independently of clinical information at renal biopsy or during follow-up); including mesangial (M) and endocapillary (E) proliferation (hypercellularity), glomerulosclerosis (S) and tubular atrophy and interstitial fibrosis (T). The scheme will likely become known as the OXFORD-MEST scoring system.