All children's A&E services will move to Leeds General Infirmary
Children's hospital services previously offered at St James's University Hospital in Leeds have been transferred to Leeds General Infirmary (LGI).
Previously, children under 16 were seen by A&E staff at both hospitals.
All children's specialists are now concentrated at a new assessment unit and bigger Children's Emergency Department at LGI.
The changes are part of wider plans to bring all children's services together creating the Leeds Children's Hospital.
The hospital will be the second biggest of its kind in the country.
'Needs of children'
Dr Kevin Reynard, consultant in emergency medicine, said: "This is a big change and provides a single service which is designed around the needs of children with all our experts in one place.
"We have been planning this move for many months and it's really important that parents and carers are aware that the service is now located at LGI."
Children's wards and departments will transfer from St James's Hospital between 21 April and 3 May.
Services which provide care for children, including the minor injuries clinic at Wharfedale Hospital, the St George's Centre, Middleton, and the NHS walk-in centre in central Leeds will continue to operate as normal.