We have reviewed the current data evaluating the effects of intravenous milrinone in patients following cardiac surgery. Milrinone has been shown to be effective in the treatment of acute low output syndrome, and a loading bolus infusion of 50 micrograms kg-1 over 10 min causes an increase in cardiac index and a fall in pulmonary capillary wedge pressure. These effects are easily maintained by a continuous infusion regimen. Other haemodynamic effects are seen, including systemic and pulmonary vasodilatation and an increase in heart rate. These effects are not confined to one patient group, but the increase in cardiac index does appear to be more pronounced in those patients with poor haemodynamics prior to treatment. There is a low incidence of adverse events including arrhythmias and hypotension. Thus milrinone appears to be well tolerated in a broad group of adult patients recovering from cardiac surgery.