The first hearing in the case was scheduled to begin Monday, Hurriyet Daily News reported.
The girl's attorney, Harika Guney Harakas, said she is concerned the men will say the girl consented to sex.
Harakas cited a case last year in which 26 men were convicted of sexually assaulting a 13-year-old girl. Their sentences were reduced because they said the girl consented.
The attorney said Turkish law is clear that no one under the age of 15 can legally consent to sex.
In the current case, 14 of the 34 men charged were released pending trial. Two of the accused are police officers, including one who has fled the country.
The girl has been in protective custody since the incident was revealed three months ago.