The acting principal Family Court judge wants the law changed so de facto and same-sex couples can adopt children.
A gap in the current legislation means single gay people can adopt, but gay couples cannot.
Judge Paul von Dadelszen says the 2004 Civil Union Act and changes to property legislation have put people in de facto relationships and same-sex couples on the same footing as married couples.
But the judge says the 1955 Adoption Act was left out of that raft of legislation, and at the moment the only people allowed to adopt a child are married, heterosexual couples.
He says the Adoption Act was drafted according to the norms of 1950s society, but is outdated and has become unjustly discriminatory.
The Catholic Archbishop of Wellington says same-sex couples do not have an automatic right to have children.
Archbishop John Dew says children have a right to be raised in a stable and committed relationship and the Catholic Church believes that is best in a married situation.
