"What She Doesn't Know" is a 7-inch single by American singer-songwriter Nina Nastasia, released on February 25, 2008 by Fat Cat Records.

[3] The two songs on "What She Doesn't Know" were recorded by Steve Albini in Chicago during the sessions for Nastasia's 2006 album On Leaving.

The B-side "Your Red Nose" features drumming by Jim White, who collaborated with Nastasia for 2007's You Follow Me.

[5] The single was released to positive reviews, with Jamie Rowland of Penny Black Music calling the two songs "brilliant examples of folk songwriting.

"[2] Tobias Kahn of The Skinny called the A-side "beautiful", but said that it "fades away too quickly.