An Amsterdam judge told the tech firm to release internet and email addresses, phone numbers and names related to four reviewers, one of whom assumed the identity of a dead woman.
Google deleted the reviews but the nursery's lawyer said it has not yet handed over the information.
Google is reviewing the decision.
The nursery, which was not named in the judge's ruling, complained that the reviews were making serious and unfounded claims that it was neglecting children, and that this was harming its business.
Three of the reviews were removed by Google for breaching its anti-spam rules after the nursery complained, including one written in the name of a woman who died in the US in November 2006. Others were found to have been copied and pasted from other websites.
In a ruling handed down last week, the judge CM Berkhout ordered the fourth to be removed because it too was in breach of the rules.
Google was given two weeks to hand over the information related to the four accounts - all of which remain active on Google+ - as well as the exact dates and times the reviews were posted. It was also told to pay more than â‚¬1,500 (Â£1,100, $1,600) to the nursery by the same date.
Paul Tjiam of Simmons and Simmons, who represented the nursery, said he believed the case would make it more difficult for fake reviewers to "hide themselves behind their computers." He added that the nursery would contact the people behind the fake reviews before deciding whether or not to pursue civil action against them.
He told the BBC that fake reviews online were not just an issue in the Netherlands, but a "worldwide problem." He said the courts' decision "shows that Google has a long way before its notice-and-take-down policy functions properly." Mr Tjiam said it was "stunning" that Google allowed the reviews to remain online. "Hopefully, another consequence of this decision is that it will make Google rethink their own policies and the way they enforce their policies."
He added: "Google's attorneys informed me that Google is still considering an appeal, but as far as I know they have not made a decision."
A Google spokesman declined to confirm that and said: "We've received the ruling and are currently reviewing it." The BBC understands that this is not the first time Google has removed reviews in the Netherlands, nor is it understood to be the first time it has been ordered to hand over internet protocol information, which identifies computers online.
Google has been ordered to hand over all contact details linked to accounts behind a series of damaging fake online reviews of a nursery.