Information is now being collected about the death of anyone aged 18 or younger, or up to 26 if they had recently been receiving care.
The mortality rate for under-18s in Scotland is higher than any other country in western Europe, with approximately 300 children and young people dying every year.
A quarter of those deaths are deemed preventable, and the Scottish Government hopes that gathering data about the causes could help reduce the number of avoidable deaths.
Public health minister Maree Todd said: “The death of any child or young person is a tragedy.
“Our ambition is for Scotland to be the best place to grow up, where every child can reach their full potential.
“We have put in place this national system so we can learn and prevent avoidable deaths or harm in the future and I welcome that it is now being rolled out.”
The death data be collected by government bodies Healthcare Improvement Scotland and the Care Inspectorate and will be studied by representatives from the health and social care sector, Police Scotland, the Procurator Fiscal and charities, with the aim of improving services or recommending changes to the law.