A man who was hit by a bus in Sydney's west last night has died.

The 31-year-old man was walking down Carlton Street, Granville, when he crossed the road and was hit by a bus about 11.20pm, police said.

The man was heading home from a nearby pub, police said.

Do you know more? Message 0424 SMS SMH (+61 424 767 764) or email us with information or images.

Police said they were investigating if alcohol had contributed to the man's death, and if he was wearing headphones.

The bus driver ran to a police station to alert officers to the man's injuries.

The victim was taken to Westmead Hospital but died from severe head trauma.

Police are asking witnesses to phone Crime Stoppers on 1800 333 000.