The tune was credited to producer George "Shadow" Morton with Jeff Barry and Ellie Greenwich. According to Morton,^[1] he wrote the song for the Goodies (also known as the Bunnies^[2]), but instead it was needed as a follow-up to the Shangri-Las hit "Remember (Walking in the Sand)". Morton claimed he credited Barry and Greenwich as co-writers for business reasons; his recollection has been questioned by Ellie Greenwich.

In July 1964, Morton recorded the vocals for the song with the Shangri-Las at the Ultrasonic Sound studio on the second floor of a Manhattan hotel. These vocals were dubbed over the instrumental parts which had been previously recorded at the Ultrasonic Recording Studios in Hempstead, New York. Billy Joel, then a young session musician, claimed he played piano on "Leader of the Pack", but this has been denied by Greenwich. In fact, the piano part was played by Roger Rossi, a staff musician for Ultrasonic Recording Studios at the time. Rossi said, "I remember the date like it was yesterday, there were no written charts, so unfortunately, some musicians kept making mistakes. As I recall, it took 63 recording takes before Shadow Morton was satisfied." Rossi added, "By the end of the session, in take 62, I also messed up and Morton laughingly yelled out, Ohhhh, ...