"I Need to Know" is the first single from Tom Petty and the Heartbreakers' second album You're Gonna Get It!. It peaked at #41 on the Billboard Hot 100 singles chart in 1978.
Stevie Nicks (of Fleetwood Mac) has been covering "I Need to Know" live in concert since 1981.
In 1981 the Swedish band Gyllene Tider recorded a version of the song with Swedish lyics, written by singer Per Gessle (the male half of Roxette), named "Vill ha ett svar!"
Poison recorded a cover of the song for their 2007 album Poison'd!....