In November, the same court found “irregularities” in the charges against them, requiring the prosecution to amend its statement.
At the time, the court also removed several pieces of evidence, finding some of the alleged victims’ statements inadmissible.
The brothers’ successful appeal on Thursday marks another setback for prosecutors.
The dual British and US nationals are accused of exploiting women through an adult content business that prosecutors say operated as a criminal enterprise.
Two Romanian accomplices were also named in an indictment released last June that named seven alleged victims.
Andrew Tate is a misogynist and has previously been banned from social media for expressing such views.
The former kickboxer gained millions of followers on social media for his politics, where he also often showed off his flamboyant lifestyle in videos.
He has been living in Romania for several years after previously being in the UK.
After the ruling in his favor on Thursday, he released a statement saying: “They have had years to build their case – years to tear my life apart, target everyone I know and even subpoena the mother of my child . And yet, they have nothing.”
He added: “It’s all a lie and I will fight to the very end to expose it and prove my innocence.”
His brother Tristan said: “If there isn’t enough evidence to go to trial after all these years, that means there never was enough evidence.”
Romania’s public prosecutor’s office, known as DIICOT, has yet to comment on the ruling.
In August, he said he had opened a second criminal investigation against the Tate brothers on new charges of trafficking minors, sex with minors and money laundering.
UK police are also seeking the extradition of the Tate brothers over rape and human trafficking charges. They are also accused of tax evasion.
The Tate brothers denied the allegations.