The caesarean birth rate in St Luke's Hospital, Kilkenny, was almost double that in Sligo General Hospital last year, according to a Health Service Executive survey of the country's 19 maternity units.
The figures show wide regional variations in caesarean section deliveries.
The data was released on foot of a request under the Freedom of Information Act, following reports to the Association for Improvements in the Maternity Services Ireland (AIMS) that intervention rates were significantly above international guidelines.
The lowest caesarean rate was found to be Sligo General Hospital with 19%.
That was followed by 21% at the National Maternity Hospital in Holles Street.
The rate for St Luke's Hospital was 38%.
Many factors are known to affect rates, including women's preferences, increasing maternal age or weight and medico-legal reasons.
Other reasons for a C-section are failure to progress during the first stage of labour, foetal distress, breech presentation and a previous C-section.
C-section rates have been increasing in developed countries.
Krysia Lynch, Co-Chair of AIMS Ireland, said: "We very much welcome the publication of this information on a per-unit basis.
"Until now, women availing of maternity services in Ireland have been in the dark about the level of interventions performed at their local maternity units and this data will help inform them about where best to have their babies.
"The statistics show that there are marked regional variations in obstetrical intervention for hospital births, for example, the C-section rate in St Luke's in Kilkenny is at a very worrying 38% compared to a 19.13% rate in Sligo General Hospital."