According to the sheet music published by Sony/ATV Music Publishing, "Can't Help But Wait" is an R&B song set in common time with a moderate R&B tempo of 112 beats per minute. It is written in the key of G minor, and follows the chord progression of Emaj7–Cm9–Gm9–Gm, and Songz' voice in the song spans from F4 to G5. "Can't Help But Wait" is about Songz wanting a woman who is mistreated by her boyfriend; he attempts to persuade the woman to leave her partner. Throughout the song, Songz gives examples of how women can be treated courteously. A remix of "Can't Help But Wait" features Lil Wayne.