Six of the eight were arrested Thursday; two others were already in custody.
Four of the defendants are members of the Rolling 60s Crips street gang and the other four are affiliated with the gang, officials said.
"Street gangs are increasingly turning to prostitution and human trafficking as a source of their revenue," said Riverside Police Chief Sergio Diaz.
The investigation began in January 2011, when the Riverside County Sheriff's Department learned that teenaged girls attending schools in the area were being recruited for prostitution, according to a statement released by the U.S. Attorney's office Thursday.
The case is being handled by the FBI, the Riverside County Sheriff's Department and the Riverside Police Department.
The investigation revealed that one of the defendants Kimberly Alberti, 19, of Riverside attended one of the schools and recruited underage females by gaining their trust and telling them that they could make large sums of money by working as prostitutes for her pimp, Samuel Rogers, also one of the defendants, officials said.
"They were able to feed these girls. They were able to house these girls. They made the lifestyle seem glamorous," said assistant U.S. Attorney Ami Sheth.
Investigators have accused Paul Edward Bell, of Lynwood, of leading the ring.
Authorities said some of the suspects could face life in prison.
The names of the victims have not been revealed and authorities said they are receiving counseling.