IgA nephropathy is the most common cause of chronic renal failure among primary glomerulonephritides. During the last decade, there was a remarkable progress in understanding its pathogenesis. A number of therapeutic trials has been published that shed light on its treatment. ACEI and AT1R antagonists (sartans) or their combination represent the cornerstone of therapy of IgA nephropathy. However, this treatment is not given to patients having optimal blood pressure, normal glomerular filtration rate, proteinuria less than 0.3 g/24 h, mild abnormalities in renal biopsy, and stationary course of the disease. The medication is administered in a maximal tolerated dose to patients with active, progressing disease. ACEI and AT1R antagonists are also drugs of the first choice in patients with proteinuric IgA nephropathy. However, if proteinuria does not decrease significantly within 3 months from the beginning of this treatment, administration of glucocorticosteroids is recommended. On the basis of prospective, controlled clinical trials and metaanalyses of other therapeutic studies, it has been concluded that glucocorticosteroids decrease proteinuria and slow down the decline of renal function. A complete remission of proteinuria is the aim of the treatment. The effectiveness of cyclophosphamide in active forms of IgA nephropathy, described in some studies, was not confirmed by metaanalyses. Nevertheless, cyclophosphamide may be effective in some patients with rapidly deteriorating renal function and active morphological findings with cellular extracapillary proliferation.