Off-label or unlicensed medicine use is very common in paediatric practice, ranging from 11 to 80 %, and is one of the predisposing factors for adverse events (23–60 %). Medicine indications are the third leading reason for doctors to perform off-label prescriptions. The aim of our study was to determine the prevalence and nature of off-label and unlicensed medicine prescriptions in children and propose methods for risk reduction and management. 475 bed maternity-paediatric university hospital. Retrospective cross-sectional study lasting 1 day on new prescriptions issued over the previous 24 h by departments using electronic prescribing. Age and indication were compared to those in the French independent formulary Thériaque® database. Number of off-label/unlicensed prescriptions, number of patients, proportion of off-label/unlicensed prescriptions by age group, treatment class and International Non proprietary Name (INN), using the established classification. A total of 315 prescription medicines were analysed for 120 patients, of average age 5.1 years old. For the classification of medicine utilisation, the majority of the medicines were prescribed as licensed (190/60.3 %), followed by off-label (115/36.5 %) and unlicensed (10/3.2 %) medicines. Alimentary tract, metabolic and nervous system medicines constituted the most widely prescribed ATC classes. At least 54 % of patients received an off-label/unlicensed medicine. The indications for these were mainly for off-label prescriptions (80/25.4 %) followed by medicines not evaluated for safety and regarding safety and efficacy in children (14/4.5 %). Pantoprazole was the most widely prescribed off-label INN for stress ulcer prevention (62 %). For risk reduction, we found esomeprazole being prescribed instead of pantoprazole; esomeprazole is indicated for children under a year old. This study reflects one given day: 36.5 % of off-label prescriptions and 3.2 % of unlicensed prescriptions in a paediatric setting. Few risk reductions for off-label number prescriptions have been found. This work confirmed the necessity of carrying out further studies in children.