The operation is to resolve a number of Mother and Baby Homes Commission queries
The Mother and Baby Homes Commission of Investigation says a test excavation is to be carried out at the site of the children's burial ground/memorial garden in Tuam, Co Galway.
It says site works in the Dublin Road Housing Estate will begin tomorrow and last for approximately five weeks.
A sample of the site will be excavated by a team of specialist archaeologists, led by a forensic archaeologist.
Works are taking place with the co-operation of An Garda Síochána.
The commission says: "The purpose of the excavation is to resolve a number of queries that the Mother and Baby Homes Commission has in relation to the interment of human remains at this location.
"This excavation will focus on timeline and stratigraphy.
"A fraction of the site will be excavated through test trenches, the location of which have been informed by a Geophysical Survey carried out at the site in October 2015."
The commission says it is grateful to the gardaí and Galway County Council for their assistance.
Almost 800 infants and young children are thought to have died at the Tuam institution.
An inter-departmental report, published in 2014, found that the remains of 474 dead children were transferred to medical schools between 1940 and 1965 without the consent of their families.
The report also found that nearly 2,000 children from the homes were put up for adoption in the United States - with little or no records on parental consent.
Local historian Catherine Corless told Newstalk Drive that there is strong support for this latest operation.