AIM The study aims to investigate the prevalence of off-label prescribing in the general paediatric ward at a major teaching hospital in Tasmania, Australia. METHOD The drug charts and medical records from two groups of 150 consecutive paediatric patients, admitted 6 months apart in July 2009 and January 2010, were studied retrospectively. Patients were required to spend at least one night in hospital and be aged less than 12 years. Each prescribed drug was compared with the approved product information to determine if the usage was off-label. Data concerning documented informed consent and adverse drug reactions were also recorded. RESULTS Three hundred patients were prescribed a total of 887 medicines. Of these, 31.8% were off-label and 57.3% of children received an off-label medication. There was no significant seasonal variation in patient characteristics or prescriptions. Drugs were most commonly off-label due to their dosage or frequency of administration. Of the 106 different drugs used, the use of 51 was off-label on at least one occasion, and for 30 drugs their use was off-label on more than 75% of occasions. The drugs most commonly used off-label were oxycodone, salbutamol and paracetamol. No informed consent documentation was identified, and two of five recorded adverse drug reactions were associated with off-label drug use. CONCLUSION Off-label use of medicines occurred frequently in paediatric inpatients. The available evidence often supported off-label medication use. An improved system for the revision of approved drug information and an Australian guideline for paediatric prescribing are needed.