Rapid fluid resuscitation is most commonly used for children with moderate-to-severe dehydration, or for patients in shock to restore circulation. Concerns regarding potential for fluid overload and electrolyte disturbances and regarding the method of rehydration (i.e., enteral versus parenteral) raise some debate about the safety and efficacy of rapid fluid resuscitation in the pediatric patient. Recent studies show that early, aggressive fluid resuscitation of up to 60 ml/kg within 1-2 h may be necessary to replenish circulating intravascular fluid volume. Complications of severe electrolyte disturbances, cerebral edema, or uncontrolled hemorrhage are uncommon and can often be avoided with early clinical assessment and reassessments throughout the resuscitation. In the mildly to moderately dehydrated child, enteral fluid resuscitation with the aid of an antiemetic such as ondansetron can be as effective and efficient as intravenous fluid resuscitation.