"I Need to Know" is a song by Marc Anthony, and was released as the lead single of his first English language album Marc Anthony, in August 1999.
 

The song was written and produced by Marc Anthony and Cory Rooney, and also a Spanish version (titled Dímelo) was released with the collaboration of Robert Blades and Angie Chirino, and the lyrics are about a man who wants to know about a woman's feelings for him, going with the title "I need to know". Both versions of the track were very successful in the United States. The English version peaked at number 3 in the Billboard Hot 100 and at number-one in the Hot Latin Tracks for 5 consecutive weeks.

This track received three Latin Grammy nominations, Song of the Year, Record of the Year and Best Male Pop Vocal Performance, winning for Song of the Year at the Latin Grammy Awards of 2000. Also on the Grammy Awards received a nomination for Best Male Pop Vocal Performance, which lost out to Sting's "Brand New Day".

"I Need To Know" was included on the compilation album NOW: That's What I Call Music Vol. 4 ^[1]. "Dímelo" was included on the compilation album released for the 1st. Latin Grammy Awards, since it was nominated for "Record of the Year" ^[2].

The opening of the song is featured in the 2008 US Nissan Versa commercial.

In 2009, the song features in the episode American Dad, Wife Insurance as a way to seduce Colombian women.