- HD 1080
- Runtime: 119m.
- Status: Released
- 1
- Languages: fr
- Country: Switzerland, France
- Director: Leos Carax
- Stars: Juliette Binoche, Denis Lavant, Michel Piccoli, Hans Meyer, Julie Delpy
- keywords: unrequited love, debt, older man younger woman relationship, ex-con, nickname, illusionist
- Production_studio: Soprofilms, Unité Trois, Limbo Film AG, Les Films Plain Chant, FR3 Films Production, Georges Reinhart Productions, Sofima, Sogedis, CNC, Théo Films
- Slogan: Love that burns fast but lasts forever.
- The Mauvais Sang is featured in the top rankings of 1986
- #11 in Top Romance Movies of 1986
- #25 in Top Drama Movies of 1986
- #7 in Top Crime Movies of 1986
Two aging crooks are given two weeks to repay a debt to a woman named The American. They recruit their recently deceased partner's son to help them break into a laboratory and steal the vaccine against STBO, a sexually transmitted disease that is sweeping the country. It's spread by having sex without emotional involvement, and most of its victims are teenagers who make love out of curiosity rather than commitment.