These findings show that: (i) off-label and/or an unlicensed prescribing is widespread among the hospitalised paediatric population worldwide, (ii) there is no consensus on a definition of off-label and/or unlicensed drugs and (iii) preterm newborns receive most off-label and/or unlicensed drugs. By shedding new light on off-label and/or unlicensed drug prescribing, these findings will hopefully contribute to generating new, more effective knowledge about the paediatric population's need for quality drugs that are both safe and efficacious.