Background: There is often a lack of safety and efficacy data in the paediatric population at the time of drug approval. Legislative efforts have promoted clinical pharmacology research in this underserved population. We sought to determine the quantity and quality of paediatric clinical pharmacology data in US drug labelling at the time of initial approval and to evaluate trends over time. Materials and methods: The labelling data of 213 new molecular entities approved between 2003 and 2012 were systematically reviewed. The type of paediatric pharmacology data present at the time of approval was recorded and stratified by age group. Labelling revisions were analysed for updated paediatric data. The presence of paediatric-speci fic black-box warnings was noted. Results: Of the 213 drugs evaluated, 48 had adult-specific indications. Of the remaining 165 medicines, only 47 (28%) had paediatric study data at the time of initial labelling. The number of approved drugs with paediatric data was the greatest in 2005 (8, 44%) and was at its lowest point in 2012 (3, 11%). Only five medicines had neonatal data, with none of the anti-infective agents presenting neonatal information. Seven medications had a paediatric-speci fic black-box warning. Additional 16 medicines presented paediatric data during general labelling updates. Conclusions: Despite efforts to improve the quality of paediatric clinical pharmacology data, there was not a significant increase in drugs with paediatric data at the time of approval over this 10-year study period. Paediatric drug approvals and labelling revisions continue to lag behind their adult counterparts.