Police are investigating the circumstances surrounding the death of a man in Sydney's north-west on Thursday evening.

At about 8.50pm, emergency services were called to Gladstone Street in North Parramatta where they located a 35-year-old man suffering wounds.

Officers from Parramatta Police Area Command attempted to provide first aid to the man, however, he died at the scene, police said.

Parramatta detectives, with the assistance of the State Crime Command's Homicide Squad, are investigating the circumstances surrounding the incident and say they would like to speak with witnesses or anyone who may have information that could assist.