Police in Waikato are hunting a woman in her 20s, who threatened a man with a knife and took his car.

The incident happened just before 10pm last night in Huntly.

Police say the woman turned up at a house in the town in a white Toyota Altezza, and took off in the man's blue Subaru Grand wagon.

The stolen car was last seen heading south on State Highway 1, with the woman and several others in it.