Glomerulonephritis is a term referring to direct injury of the glomeruli with resulting disturbances of normal glomerular function, progressively leading to renal failure. Glomerular diseases are classified as primary, where glomerular damage is the prime disturbance, with extrarenal manifestations as a result of renal impairment, and secondary, following systemic disorders, infections or exposure to certain drugs. Although noteworthy progress has been made in the past years in the symptomatic and specific treatment, therapy of both primary and secondary glomerulonephritis can be challenging. Management of these patients requires early diagnosis, expert knowledge of the immunosuppressive agents and other drugs currently available for the treatment of each glomerulonephritis, consideration of possible adverse reactions to these drugs, alternative therapeutic strategies in cases of hyporesponsiveness or non-responsiveness of the patient to the treatment, and possible relapses of the disease. This book reviews knowledge of the main primary and secondary glomerulonephritis, with emphasis on current therapeutic strategies and practical recommendations. Glomerulonephritis are grouped according the presence or absence of proliferative histological alternations into primary and secondary proliferative and non-proliferative types. Each chapter deals with etiopathogenesis, epidemiology, pathology, clinical manifestations, natural history and therapeutic options of the commonest primary and secondary glomerular diseases, with exception the last chapter that covers inherited diseases with renal involvement. An atlas of the pathology of the glomerular diseases discussed completes this work.