The song contains an interpolation of the theme for the film Midnight Cowboy (1969).
"Baby I Love U" is an R&B ballad about unconditional love, with critics pointing out that it was inspired by Lopez's relationship with the actor Ben Affleck.
The song was as successful as the other singles from the album in the United Kingdom, where it peaked at number three.
In the United States, the song peaked at number 72 on the Billboard Hot 100, and reached the top 30 of the Mainstream Top 40 chart.
A remix version featuring R. Kelly was released on the CD single of the song. Kelly's part talks about 'rollin' with 'some fine females' against J-Lo's heart-on-the-sleeve declaration of passion.