A 50-year-old man has been stabbed to death during a "domestic incident" involving another man at a home in western Sydney.

The victim suffered multiple stab wounds in the attack on Waikanda Crescent, Whalan, at about 5.30pm on Saturday.

Emergency services attended the home but the man died at the scene.

A woman and child in the townhouse were not injured.

A 20-year-old man was arrested nearby, and taken to Mt Druitt Police Station. Charges are yet to be laid.

Local resident Sandra Shepherd told AAP she saw police at the townhouses at the end of her street, which backs onto Waikanda.

"There was a helicopter circling, this type of thing happens a lot," she said.

"The townhouses have a bit of problems."

AAP