New figures show 759 same-sex couples tied the knot here in 2017.
The CSO says 424 of these were male unions and 335 were female.
But that's a drop when compared to 2016, when 1,056 same-sex couples said 'I do'.
The average age of couples in same-sex marriages was 40.4 years, with 69% opting for civil marriage ceremonies.
Over one-third of all same sex marriage ceremonies took place Dublin City.
September was the most popular month for same-sex marriages, with Sunday being the least popular day.
More than 78% of same sex marriages were first time marriages.
It comes three years after the country voted to legalise same-sex marriage.
