Inside Victoria's Secret's Fashion Show Casting

The Victoria's Secret Fashion Show supermodels are set in stone, but a few more lucky models will be slotted in the show, and ET was granted exclusive access to hang out with the models during a recent casting session.

As the show has become such a grand production, show producer Monica Mitro revealed that the casting process for this year's models began around the same time that last year's fashion show happened.

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"We really start thinking about it a year in advance and we see girls all year long," she said. "During these two days, we see all the callbacks, all the girls that we've liked throughout the year, the girls that we might have seen in magazines or in other shows or that we have shot ourselves that we wanted to try for the runway...It's a long process."

While all but one of the models with whom ET spoke had walked the runway in the show in previous years, they revealed that the nerves were still there when they had to model for the show producers and casting director.

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"It's always nerve-wracking, you know? There's a panel of people we got to walk [in front of]," said model Jessica Clark, "but they're lovely. They're awesome, and it's like a family."

The show, which attracted over 10 million viewers last year in its ninth year on CBS, has become a milestone for aspiring models that have grown up watching the show since it was first telecasted in 2001.

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"I grew up watching [the] Victoria's Secret show and it was such a daydream and it takes you to this fantasy world that you want to be a part of," said Puerto Rican model Joan Smalls. "Now that I'm actually here doing the casting and last season was my last show, it's quite a memorable experience."

The Victoria's Secret Fashion Show will air December 4 at 10 p.m. on CBS.