Controversy regarding fluid therapy for major surgery dates back to the 1950s and is largely based on two differing concepts: the first, that the metabolic and stress response to surgery causes water and sodium retention, and the second, that there is redistribution of fluid into a hypothetical ‘third space’ leading to a fall in intravascular volume. Aggressive perioperative fluid resuscitation is the standard of care provided by many anaesthetists, however, evidence seems to suggest that this is flawed. Unfortunately, the answer is not as simple as following a restrictive fluid regimen.