A trial for the four men had been scheduled for Jan. 16.
"We feel it was the result of everyone taking a second look at this matter in light of new evidence," said Steve Graham, attorney for band member Waclaw Kieltyka, 35.
"They are headed back home this week," Graham said of the band members.
Kelly Fitzgerald, a Spokane County deputy prosecutor handling the case, was not immediately available for comment.
The charges were dismissed without prejudice, meaning the four men could be charged again in the future.
According to court documents, a woman told police that she was invited onto the tour bus after the band's show on Aug. 31. The woman claimed that she was raped in the bathroom of the bus.
Band members were arrested in Los Angeles County, California, after a show there Sept. 9 and extradited to Spokane.
The other three band members are Michal Lysejko, 27; Rafal Piotrowski, 31; and Hubert Wiecek, 30.
The state's case largely consisted of testimony from two women who told police that they were held against their will on the band's tour bus after the show. One of the women was able to get off the bus.
The woman who remained on the bus told police that she was raped by each member of the band. Later at a hospital, police noted significant bruising and abrasions on her arms that were "consistent with being restrained," according to court documents.
But defense attorneys said in court documents that numerous witnesses placed the woman in the front row of a mosh pit at the concert and said she was getting jostled, which could have accounted for the bruises.
Graham said the case against the four men was falling apart.
The band members had been out of jail since late last year, when bail was dropped and they were released on their own recognizance.
"All the guys are interested in putting this behind them and moving on," Graham said.