The 29-year-old actress was joined on the stage by Rob Lowe.
Pierce Brosnan also made an appearance at the telecast, where he opened up about his wife Cassandra Harris and daughter Charlotte, who both died from ovarian cancer.
“The stars of @Su2c are calling you tonight! Sign up for the chance to talk to your favorite celebs! #werecallingyou,” Anna tweeted earlier in the day.
It was just announced that Anna‘s upcoming movie musical The Last Five Years, which will premiere this weekend in Toronto, will get released on Valentine’s Day 2015!
10+ pictures inside of Anna Kendrick and Rob Lowe on stage at the Stand Up To Cancer telecast… More Here! »