A WOMAN appeared at East Perth Magistrate's Court today charged in relation to the fatal stabbing of her defacto partner in St James.

Thi Nguyen, 45, has been charged with grievous bodily harm over the incident however police have said the charges could be upgraded depending on the result of a post mortem examination.

Police said they were called to the Buzza Street property at around 9.45am Friday where they discovered a man with serious injuries.

The 43-year-old was rushed to hospital with stab wounds to the chest. He died a short time later.

There were reports that neighbours heard shouting coming from the house before police were called.

Ms Nguyen, who did not apply for bail, was remanded into custody and will reappear at Perth Magistrate's Court in a week.

The St James incident is the fifth suspicious death in WA this week.

A Girrawheen man has been charged with two counts of murder after allegedly killing his 31-year-old wife and a 37-year-old male friend at two separate houses in the suburb on Wednesday afternoon.

Detectives are questioning several people over the death of Richard Holloway, 42, who was found bashed to death in his South Perth apartment on Tuesday.

And Daniel Luke Zwerus, 31, faced Perth Magistrates Court this week charged with the murder of Halls Head man Ilario Maiolo.

The 46-year-old's body was found at the local dog beach near Boardwalk Boulevard and Montego Way about 11.30am on Monday. He had been stabbed.