A 45-year-old man died on Thursday evening from stab wounds to the chest at a house in Luen On New Village in Tuen Mun.
Police said at about 10:30 pm, a 39-year-old woman reported that her husband had been stabbed and injured.
Ambulancemen arrived, but the man died from his injuries at the scene.
The police said they considered the incident suspicious and the woman who made the report was taken to the local police station to assist with their enquiries.