A woman has been arrested after a passer-by found a man with stab wounds in a street in Moorabbin, south-east of Melbourne, in the early hours of Saturday.

The injured man, who is yet to be identified, was found on Keys Road near Herald Street just before 1am.

The man was taken to The Alfred hospital with upper body injuries.

An Ambulance Victoria spokesman said he was in a serious but stable condition.

A 22-year-old woman from Sydenham was arrested a short time later and remained in custody on Saturday afternoon.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au.