Mormon Church rules state members should donate 10pc of their income to the church through a 'tithe'.
Newly filed accounts for the Irish branch of the church show that tithing income totalled €687,148 last year -- a 28.6pc drop on the €962,863 received in 2010.
The drop in tithing income comes in spite of church numbers in Ireland increasing by 16pc last year from 2,514 to 2,915.
Despite the drop in income, Ben O'Farrell, director of the Irish Association of the Church of Jesus Christ of Latter Day Saints, said that the church was in good health.
"The tithe income allows us to be self-sufficient and we have no debt," he said.
Mr O'Farrell added that "increased unemployment and emigration amongst our members resulted in the drop in tithe income last year".
He added that a good portion of new members last year would have included children, who do not pay a tithe.
Members are not allowed to drink or smoke, while Mr O'Farrell said that in one Dublin branch, young members aged 14 to 18 are attending Bible classes four mornings a week at 6.30am before attending school.
Mr O'Farrell said that US presidential candidate Mitt Romney, who is a Mormon, has raised the profile of the church here.