An average of less than 30 children a day have attended the new paediatric urgent care centre in Blanchardstown since it opened.
It is the first phase of the national children's hospital project, which is set to cost €1.7bn.
The facility in Connolly Hospital in Dublin opened at the end of July and caters for children with minor injuries and illnesses.
Because of a shortage of senior doctors, it opens only from 10am to 5pm, Monday to Friday.
According to details released under the Freedom of Information Act, 2,756 children presented to the centre between July 31 and December 13, which is an average of 28 a day.
Dr Ciara Martin, a consultant in paediatric emergency medicine with Children's Health Ireland which runs the centre, said there has been a big increase in attendances recently.
Dr Martin said: "Our numbers have doubled in the last six weeks and we are seeing up to 60-80 children a day now.
"When we opened we were hoping to see about 70 children a day over 16 hours, but now we are seeing about 60-8- over the seven hours of opening."
The average amount of time spent by patients in the urgent care centre is just under two-and-a-half hours.
Half of those seen were aged five or less, while just over a third were aged between six and 12.
The remaining 397 children were over 13 years old.