A Supreme Court judge says Ireland needs to draft legislation to clarify the rights of polygamous families.
It's after a ruling on the marriage of a Lebanese man and his two wives who live here.
The 64 year old tied the knot with his first wife in 1975 and his second in 1988. They have a number of children.
The man came to Ireland in 1998.
The panel found that the man's first marriage is valid under Irish law but the second is not.
However Justice Iseult O'Malley said "there's no particular reason why a marriage should not be given recognition for certain purposes as has been done in many instances in the courts of the UK."
The court heard there are around 60,000 Muslims living in Ireland but not very many polygamous marriages are known about.