Two cases of 10-fold accidental overdose with intravenous paracetamol are presented. Case 1: A 5-month-old child with intussusception received 90 mg/kg intravenous paracetamol over an 8 h period. She was not initially treated with an antidote and developed hepatic impairment. Case 2: A 6-month-old child received a single dose of 75 mg/kg intravenous paracetamol. The child was treated with N-acetylcysteine and remained well without hepatic impairment. Therapeutic errors such as 10-fold overdosing are relatively common in children. Case 1 demonstrates that intravenous paracetamol is a potentially dangerous drug. This should be taken into consideration when prescribing the intravenous formulation. The concentration-time nomogram used following oral paracetamol overdose should be used with caution following intravenous overdose. Significant overdose should be discussed with the National Poisons Information Service whose guidance suggests intervention with antidote following an overdose above 60 mg/kg.