A junior doctor has been charged with manslaughter after he allegedly choked an older man who passed out and later died in hospital.

Christian Jack Joseph, 26, was arrested at his friend's home at South Terrace, in southwest Perth, about 1.30am on Saturday.

He and his friend had spent the night out in nearby Fremantle and were returning home when they allegedly found the man, 63, peering through a window of the South Terrace home.

The two friends allegedly yelled at and chased the man until Joseph is accused of pinning him to the ground and holding him in a chokehold, WA Today reported.

When Joseph realised the man had fallen unconscious, he began performing CPR and instructed his friend to call triple zero.

The 63-year-old was taken to Fiona Stanley Hospital, where he later died.

Joseph, a junior doctor at Sir Charles Gairdner Hospital, was arrested and charged with manslaughter.

He appeared in Perth Magistrates Court on Sunday while still wearing a blue forensics jumpsuit. 

The 26-year-old lives in Crawley and studied medicine at the University of Western Australia.

Joseph's lawyer said he had acted in self-defence and was 'intimidated' by the older man's behaviour.

The lawyer added it was unclear why the man had fallen unconscious in a short span of time.

The court, which was filled with Joseph's family and supporters, heard the alleged attack was 'out of character' for the young doctor who is 'dedicated to saving lives'.

Prosecutors noted it was unclear what the 63-year-old man was doing at the window and there was CCTV of the event.

The magistrate noted the charge was too serious to grant Joseph bail and denied a request to suppress his name in the media. 

'Any reporting will be worrying to the accused, but I'm not satisfied that there are sufficient grounds to suppress his name,' the magistrate said.

Joseph is due to appear in Stirling Gardens Magistrates Court on August 5.