The alarm came shortly after 19:00 on Friday about a stabbing at an address in Ed, in the municipality of Dals-Ed.
An injured man was found inside the home and was later taken to hospital.
– The extent of the injuries is still unclear, but the man was awake and able to speak when he was taken from the scene, says Jens Andersson, press officer at police region West.
Inside the home, a woman was arrested on suspicion of attempted murder, the police say. The residence in question has been cordoned off for a technical examination.