On April 3, 2009, the Iowa Supreme Court unanimously struck down the 1998 state ban on marriage for same-sex couples.

The case was brought by Lambda Legal on behalf of six same-sex couples. NCLR submitted an amicus brief with co-counsel McGuire Woods LLP and Joseph Barron, Esq. on behalf of several professors of family law in support of the couples, addressing the use of social science research in constitutional cases. This is the fourth state supreme court to rule that same-sex couples must be permitted to marry under state law.