Background: We investigated time trends in age, gender, growth hormone (GH) dose and height standard deviation score (SDS) in children with GH deficiency (GHD), born small for gestational age (SGA) or with Turner syndrome (TS) starting GH treatment. Methods: Data were obtained from children enrolled in the NordiNet® International Outcome Study (IOS) between 2006 and 2015 in the Czech Republic, France, Germany, Serbia and Montenegro (all indications), and Switzerland and the UK (GHD only). Trends were analyzed by linear regression. Patients were divided by age into early-, medium- or late-start groups in three different time periods. Results: Approximately one-third of children starting treatment for GHD were girls, with no apparent increase in proportion over time. The mean baseline age for starting treatment decreased significantly (p<0.001) for both GHD and SGA in the Czech Republic and Germany. In the other countries studied, over 40% of children started treatment for GHD and SGA late (girls >10, boys >11 years) between 2013 and 2015. The mean baseline GH doses were largely within recommended ranges for GHD and SGA, but below the lowest recommended starting dose for TS in almost every year since 2011 except in France. Conclusions: Approximately one-third of children starting treatment for GHD were girls. Between 2013 and 2015, more than 40% of children started treatment for GHD and SGA late except in Germany and the Czech Republic. TS patients received below-recommended doses. These results highlight the need for earlier identification of short stature in children, particularly girls, and for dose optimization in TS.