Acute renal failure (ARF) is a common condition in hospitalized patients. The aetiology and physiological characteristics differ from those of chronic renal failure (CRF) and both conditions should be approached differently. At present, the approach to the management of ARF is very heterogeneous. Attempts have therefore been made to improve consensus and to standardize treatment in the Acute Dialysis Quality Initiative (ADQI). Technology for the treatment of ARF is expanding. Traditional intermittent haemodialysis (IHD) is still a major treatment modality but continuous renal replacement therapies (CRRT) and slow, low-efficiency daily dialysis (SLEDD) are commonly used alternatives. Each modality has advantages and disadvantages, but to date no evidence exists for the superiority of one over the other. On the other hand, the availability of multiple options allows us to provide tailor-made treatment: the best modality is chosen depending on local expertise and the individual clinical scenario. Practice guidelines based on the best available evidence and the author's opinion are suggested.