Sepsis and septic shock are the final common pathway for many decompensated paediatric infections. Fluid resuscitation therapy has been the cornerstone of haemodynamic resuscitation in these children. Good evidence for equivalence between 0.9% saline and 4% albumin, with the relative expense of the latter, has meant that 0.9% saline is currently the most commonly used resuscitation fluid world-wide. Evidence for harm from the chloride load in 0.9% saline has generated interest in balanced solutions as first line resuscitation fluids. Their safety has been well established in observational studies, and they may well be the most reasonable default fluid for resuscitation. Semi-synthetic colloids have been associated with renal dysfunction and death and should be avoided. There is evidence for harm from excessive administration of any resuscitation fluid. Resuscitation fluid volumes should be treated in the same way as the dose of any other intravenously administered medication, and the potential benefits versus harms for the individual patient weighed prior to administration.