"I Hear You Knocking" reached number two on the Billboard R&B singles chart in 1955, making it Lewis's most popular and best-known song.

Subsequently, numerous artists have recorded it, including Welsh singer and guitarist Dave Edmunds, whose version reached number one in the UK Singles Chart for six weeks in 1970 and was in the top 10 in several other countries.

However, when popular jump blues bandleader Louis Jordan and his Tympany Five recorded the song as "Keep A-Knockin'" in 1939,[6] the single's credits listed "Mays-Bradford" (Bert Mays and Perry Bradford).

[2] Beginning with his signing by the Los Angeles–based Imperial Records in 1950, Smiley Lewis was one of the main proponents of the emerging New Orleans rhythm and blues style, along with Fats Domino, Lloyd Price, Dave Bartholomew, and Professor Longhair.

Smiley Lewis recorded "I Hear You Knocking" with Dave Bartholomew's band at J&M Studios in New Orleans, owned by Cosimo Matassa.

[7] "I Hear You Knocking" uses a modified twelve-bar blues arrangement, in which the progression to the IV chord is repeated:[8] It has been notated in 4/4 time in the key of C with a moderate tempo.

"[13] The experience reportedly led Bartholomew to refer to Lewis as a "'bad luck singer', because he never sold more than 100,000 copies of his Imperial singles".

[16] Whereas Lewis's original recording is a piano-driven R&B piece with a 12/8 shuffle feel, Edmunds' version features prominent guitar lines and a stripped-down, straight-quaver rock-and-roll approach.

[17] He plays all the instruments (except possibly bass guitar) and AllMusic writer Stephen Thomas Erlewine suggests that the song "has a mechanical rhythm and a weird, out-of-phase vocal that qualifies as an original interpretation".