Man held over stabbing in Sydney's west

A man is in custody after another man was stabbed multiple times in Western Sydney overnight.

Emergency services were called to Post Office Lane at Merrylands about 11pm yesterday and found a 38-year-old man with multiple stab wounds being helped by passers-by.

He was treated at the scene by paramedics before being taken to Westmead Hospital in a serious but stable condition.

Police believe the man was stabbed following an argument with another person, shortly before he was found injured.

After setting up a crime scene, officers arrested a 30-year-old man outside a home in Newman Street, Merrylands.

He was found with items including a knife, which has been taken for forensic examination.

Anyone with information about the incident is urged to contact Crime Stoppers on 1800 333 000.