Emergency services rushed to Marrickville Road in Marrickville about 7.40pm today in response to reports a man had been stabbed.
Police and paramedics performed CPR but he died at the scene.
Officers established a crime scene and closed several streets in the area.
“These closures are expected to remain in place for a considerable amount of time and motorists are urged to avoid the area,” police said, in a statement.
They called for anyone with information or footage of the incident to contact Marrickville police station or Crime Stoppers on 1800 333 000.
