As a nurse, Coffy (Pam Grier) has seen the ill effects of drugs up close, but it isn't until her little sister becomes addicted to heroin that she finally decides to wage a one-woman battle. Disguised as a prostitute, Coffy goes on a killing rampage, at first going after street dealers and pimps such as sleazy King George (Robert DoQui), then gradually working her way up to bigger honchos. She's shocked, however, when she discovers that her politician boyfriend (Booker Bradshaw) is involved.