Ketamine 3–6 mg kg−1 given by mouth to paediatric patients for anaesthetic premedication was evaluated. Forty-three children, ages 2–9 years were randomly allocated to receive either ketamine (3 or 6mg kg−1) or placebo (cola 0.2 mL kg−1). Oral use of ketamine made separation from the families easier, gave an increased level of sedation, made acceptance of mask application easier and improved the emotional state in the recovery phase. These improvements were present with ketamine 3mg kg−1 and 6mg kg−1 in comparison with the placebo. We conclude that 3mg kg−1 ketamine given by mouth to premedicate paediatric patients is as effective as 6mg kg−1 but has a decreased incidence of side effects such as nystagmus and vomiting.