9 7 9 , ▁through ▁Cas ab lan ca ▁Records . ▁The ▁song ▁was ▁produced ▁by ▁Summer ' s ▁regular ▁collabor ators ▁Giorg io ▁Mor oder ▁and ▁P ete ▁Bell otte , ▁and ▁co - written ▁by ▁Summer ▁and ▁the ▁Brook lyn ▁Dream s . ▁ ▁" Bad ▁Girls " ▁became ▁a ▁world wide ▁success , ▁pe aking ▁within ▁the ▁top - ten ▁in ▁seven ▁countries , ▁including ▁Spain ▁and ▁New ▁Zealand . ▁In ▁the ▁United ▁States , ▁it ▁spent ▁five ▁weeks ▁at ▁number - one ▁on ▁the ▁Billboard ▁Hot ▁ 1 0 0 , ▁from ▁the ▁weeks ▁of ▁July ▁ 1 4 , ▁ 1 9 7 9 ▁to ▁August ▁ 1 1 , ▁ 1 9 7 9 ; ▁and ▁sold ▁over ▁two ▁million ▁copies , ▁simultaneously ▁becoming , ▁alongside ▁" Hot ▁St uff ", ▁her ▁most ▁successful ▁single . ▁The ▁single , ▁which ▁was ▁the ▁second - big gest ▁song ▁of ▁ 1 9 7 9 , ▁also ▁helped ▁the ▁Bad ▁Girls ▁album ▁to ▁reach ▁the ▁multi - pl atin um ▁status ▁in ▁the ▁US . ▁Summer ▁placed ▁three ▁songs ▁in ▁the ▁Top ▁ 1 2 ▁of ▁the ▁Billboard ▁ 1 9 7 9 ▁year - end ▁charts . ▁ ▁Background ▁ ▁The ▁insp iration ▁for ▁Summer ▁to ▁write ▁the ▁song ▁came ▁after ▁one ▁of ▁her ▁assist ants ▁was ▁off ended ▁by ▁a ▁police ▁officer ▁who ▁thought ▁she ▁was ▁a ▁street ▁prost itute . ▁A ▁rough ▁version ▁of ▁the ▁song ▁had ▁originally ▁been ▁written ▁a ▁couple ▁of ▁years ▁before ▁its