Around a year after a bill was introduced, parliament voted in favour yesterday but without the support of the government.
Opposition politicians, with some breakaway members of the government’s Liberal Party, backed the new rights, which give partnered gay couples the same rights as straight married couples.
Previously, gays and lesbians could adopt individually in the country and couples can adopt their partner’s existing children.
According to figures from 2007, 103 out of 712 step-child adoptions were from couples in civil partnerships.
Other Nordic countries such as Iceland, Norway and Sweden already allow same-sex couples to adopt jointly
The new legislation was welcomed by the Danish National Association of Gays & Lesbians (LGBT Denmark).
LGBT Denmark’s Hans Christian Seidelin told the Copenhagen Post: "The most important thing is that in the future it won’t be rigid legislation but a qualified adoption authority that will make the decision about who would make a suitable adopter."