A gay couple has been granted full parenting rights to their daughters who were conceived using an overseas surrogate mother.

The Melbourne men had twins through an Indian surrogate mother last year, using sperm from one of the men and an egg from an anonymous donor.

Now a Family Court decision has granted the non-genetic father full parenting rights.

Victorian Law Institute president Caroline Counsel says the decision from Justice Paul Cronin sets an interesting precedent.

"I think what's interesting is that Justice Cronin calls the two gay men 'the father of these children' because parenting or parents are not described under the Family Law Act as being the mother [and] the father," she said.

"So we have a situation where the court is saying 'there is such a phenomenon as two fathers'.

"He really is saying 'what is a family? A family can be any combination of parents; the important thing is the joint parental responsibility that the people have in raising children in Australia'."