Sofia and Andrea, a couple who have been married for ten years, are now on the brink of divorce. He is a brilliant neurosurgeon who is conducting an experiment on the human brain, while she is an ambitious TV presenter whose career is on the up. Following one of Andrea's science experiments, they both suddenly find themselves literally occupying each other's bodies, with each having no choice but to carry on with the life and daily routine of the other.
Two couples, Pierre and Aimée, Éric and Pénélope, all share four years of friendship without cloud. Only concern, Penelope and Pierre have become lovers - The situation becoming untenable, they decide to break. But after a final night of passionate love, fate plays a trick on them: Peter and Penelope each wake up in the body of the other. To protect their secrecy, they each find themselves having to live the life of the other. This is the beginning of the complications.
Billionaire industrialist Damian Hale (Ben Kingsley) is master of his universe, until he encounters a foe that he can't defeat: cancer. His only hope is a radical medical procedure called "shedding," in which his consciousness is transferred to a healthy body. After the procedure, Damian, now called Edward (Ryan Reynolds), starts a new life in New Orleans, but he's plagued by disturbing images. When he delves into Edward's mysterious origin, he learns that some will kill to keep it secret.
Once inseparable pals, Dave (Jason Bateman) and Mitch (Ryan Reynolds) have drifted apart over the years. Dave is an overworked lawyer and family man, while Mitch has thus far avoided most of the normal responsibilities of adulthood. Each is envious of the other's life, and following a drunken binge, the men awake to find they have somehow switched bodies. Dave and Mitch soon discover that things are not as rosy as they seemed and try to find a way to return their lives to normal.
A serial killer returns to his hometown to stalk seven children who share the same birthday as the date he was allegedly put to rest.
Pretty teen girl Nell (Samaire Armstrong) is extremely bookish and can't wait to move on to higher education, while her dim-witted neighbor and classmate, Woody (Kevin Zegers), wants nothing more than to play football. When a class trip to a museum places Nell and Woody under an ancient Incan spell, the two awake the next day to find that they've switched bodies. As they cope with their bizarre situation, Nell and Woody realize that they must discover a way to reverse the spell.
Single mother Tess Coleman (Jamie Lee Curtis) and her teenage daughter Anna (Lindsay Lohan) couldn't be more different, and it is driving them both insane. After receiving cryptic fortunes at a Chinese restaurant, the two wake up the next day to discover that they have somehow switched bodies. Unable to switch back, they are forced to masquerade as one another until a solution can be found. In the process, they develop a new sense of respect and understanding for one another.
Not only is Jessica Spencer (Rachel McAdams) the most popular girl in school -- she is also the meanest. But things change for the attractive teen when a freak accident involving a cursed pair of earrings and a chance encounter at a gas station causes her to switch bodies with Clive (Rob Schneider), a sleazy crook. Jessica, in the form of the repulsive Clive, struggles to adjust to this radical alteration and sets out to get her own body back before the upcoming prom.
One messy science journalist (Tash) and a neat television host (Brett). Two very different people whose relationship is nose diving to get the opportunity to experience life in their partners shoes when they wake up one morning in each others bodies. Valuable lessons are learned by each as they both have to adjust to very different lives.