1. Low-dose ('renal-dose') dopamine (i.e. 1-3 micrograms/kg per min) is used widely for the treatment of acute renal failure induced by ischaemia, toxins and/or sepsis. Here we review the scientific rationale, experimental studies and clinical trials evaluating its use in these settings. 2. Renal-dose dopamine augments renal blood flow, sodium excretion and probably glomerular filtration rate in healthy humans and experimental animals and limits ATP utilization and oxygen requirements in nephron segments at risk of ischaemic injury. Renal-dose dopamine is renoprotective in several ischaemic and nephrotoxic models of acute renal failure. 3. However, most studies in humans have not demonstrated prevention of acute renal failure in high-risk patients or improved outcome in those with established acute renal failure. While the safety profile of dopamine in these settings has not been extensively defined, it is known the drug may precipitate serious cardiovascular and metabolic complications in the critically ill. Therefore, we suggest that renal-dose dopamine should not be used for selective renal vasodilatory and natriuretic actions in those patients with acute renal failure until its efficacy is established in randomized control trials. 4. Renal-dose dopamine may be most valuable when combined with agents targeting other events in acute renal failure, such as cast formation, epithelial cell injury and tubule regeneration. These recommendations should not preclude the use of dopamine for its systemic effects in heart failure and septic shock.