In the episode, Max (Kat Dennings) and Caroline (Beth Behrs) get a call from a Keeping Up With the Kardashians producer who asks permission to shoot part of the show at the girls' cupcake shop.
Kim, who plays herself on the show, surprises the girls with a special visit.
"I've done acting a little bit, but it's not typically what I do," Kim told ET on set. "It's always fun to just get out and do something new and fun."
That includes dropping by a series she's already watching. "I'm a fan of the show," Kim said. "I think it's super cute."
Kim recently lent her voice to the FOX animated series American Dad!, but her most meaty role to date was in Tyler Perry's 2013 drama Temptation: Confessions of a Marriage Counselor.
On 2 Broke Girls, Kat's character Max claims to not be a fan of the Kardashians, in real life both Kat and Beth admitted to keeping close tabs on the popular reality show.
"We binge watch and drink wine," Beth confessed. "I think I'm a mix between Kim and Kourtney."
"I'm a Khloe!" said Kat, who has recently started dating singer Josh Groban.
The new season of 2 Broke Girls premieres Monday, Oct. 27, at 8/7c on CBS.