The Harmony Korine-directed film, which stars Franco, Gomez, Vanessa Hudgens and Ashley Benson, focuses on a group of college girls who become entangled with a drug and arms dealer.
"I thought Harmony was so smart to cast [Gomez], Vanessa and Ashley because it seemed like they were so hungry for some deeper kind of material, hungry for indie material," Franco told E! Online.
"They really gave their all when they were acting," he added. "You've got great performances."
He went on to say that Korine was also attracted to casting popular celebrities in an indie film.
"They other thing that [Korine] got was this crazy fusion of high pop and like dirty indie sensibilities," Franco continued. "I think that is going to be very powerful."
Gomez recently said that Spring Breakers is "completely different" to any film of which she's ever been a part.
> Selena Gomez shows off new look for upcoming movie - pictures
Spring Breakers will be released in 2013.