Impairment of renal function, severe proteinuria and arterial hypertension are the strongest clinical predictors of an unfavorable outcome in IgA nephropathy (IgAN). Glomerulosclerosis and interstitial fibrosis are the most reliable histologic prognostic markers. Metabolic syndrome and insulin resistance probably affect the clinical course of the disease. Among the known gene polymorphism it seems that there is a link between the ACE gene D allele and the progression of IgAN. Elevated blood pressure should be actively treated. The target blood pressure is 130/80 mmHg or less and the goal should also be to reduce proteinuria. Several large-scale trials are currently testing corticosteroids and other drugs in the treatment of IgAN.