Earlier this summer the Department of Education was refusing to budge on the appointment of a second junior infant teacher.
However, the school, parents and politicians pressed for the decision to be reversed.
The Department relented and a second teacher was appointed.
The decision to have a second class was fully justified.
Some 44 children turned up on Thursday morning last to start at the Ballydoogan school.
They were divided into two classes being taught by Lynne Ni Ghiolla and Katriona Ui Chiarragain.
There are now nine classes at the school and space is at a premium.
Space is at a premium but a prefabricated building is on the way and should soon be operational.
Principal Mícheál Ó Broin says the demand for places at Sligo's only gaelscoil is continuing to rise.
"We're looking at two junior infant classes next year as well," he said.
The gaelscoil was set up in Sligo in 1996.
– See more at: http://www.independent.ie/regionals/sligochampion/news/campaign-pays-off-as-44-start-at-gaelscoil-30554545.html#sthash.CrhEx9k4.dpuf