This chapter discusses about the diagnoses and diagnostic categories for kidney transplantation, such as congenital, rare familial and metabolic disorders, diabetes, glomerular diseases, hypertensive nephrosclerosis, neoplasms, polycystic kidneys, vascular diseases, retransplant or graft failure, and tubular or interstitial diseases. Tubular and interstitial diseases include drug related interstitial nephritis, analgesic nephropathy, sickle cell anemia, sarcoidosis, urolithiasis, and cancer chemotherapy-induced nephritis. Glomerular diseases include anti-glomerular basement membrane, chronic glomerulonephritis, HIV nephropathy, membranous nephropathy, and hemolytic uremic syndrome. Metabolic disorders include congenital obstructive uropathy, Fabry’s disease, hypoplasia, dysplasia, dysgenesis, agenesis, medullary cystic disease, nephrophthisis, and prune belly syndrome. Renovascular and other vascular diseases include hepatorenal syndrome, cholesterol embolization, chronic nephrosclerosis, progressive systemic sclerosis, renal artery thrombosis, and scleroderma.