A man has been stabbed by a stranger in a random attack as he walked along a Melbourne street.

The man in his 30s was seriously injured when he was stabbed to the upper body as he walked along Cranbourne Road, Frankston about 7.15am on Wednesday.

Paramedics stabilised him at the scene before taking him to The Alfred hospital, Ambulance Victoria says.

Police have set up a crime scene on Cranbourne Road between Coprosma Avenue and Lindam Road, Frankston.

No arrests have been made and anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au