In France, administration of premixed 50% nitrous oxide and oxygen for procedural sedation is under close supervision by the French Drug Agency before final approval for use. We have examined the frequency of adverse events in children sedated with 50% nitrous oxide and oxygen over a broad range of non-specialised facilities. A mean of 0.33% (SD 0.10) children had major adverse events. Thus, premixed 50% nitrous oxide and oxygen seems to be a safe option for procedural sedation in children.