DioGuardi has a songwriting catalog of several hundred songs, of which over 279 have been released on major labels worldwide, and over 169 have appeared on multi-platinum selling albums. She has had nearly 50 international charting singles over the course of her career, and her songs have helped propel 58 albums into the Top Ten of the Billboard 200. Her songs have been featured in major motion pictures, television shows, film soundtracks, and radio spots, as well as national and international commercial campaigns.

Among DioGuardi's projects is the song "Not Meant To Be", which appears on Theory of a Deadman's 2008 album, Scars & Souvenirs.^[13] DioGuardi co-wrote the song with lead singer Tyler Connolly, and is also featured as the love interest in the music video which was released on March 10, 2009. This was her debut in the music video industry.