A two-year-old boy is fighting for life in hospital after he ran from a house onto a suburban street and was hit by a car in Melbourne's south-west last night.

Key points: A two-year-old boy is in a serious but stable condition in hospital

A two-year-old boy is in a serious but stable condition in hospital The toddler ran from a home and onto a street before being hit by the car

The toddler ran from a home and onto a street before being hit by the car Police have arrested a 21-year-old man after finding the car at a shopping centre

Police said the boy's family realised he was missing from a house on Railway Avenue, Laverton, and were attempting to catch up to him when he ran onto the road and was hit by a station wagon about 8:45pm on Sunday.

The driver of the vehicle allegedly failed to stop after hitting the boy.

Police found the station wagon at a shopping centre carpark shortly afterwards and arrested a 21-year-old Laverton man at another house on Railway Ave.

The man, who was a learner driver, was charged with failing to stop, failing to render assistance and driving without a full licence.

The boy had run out onto the street before he was hit by the car. ( ABC News: James Hancock )

Detective Acting Sergeant Michael Howard said the boy was critically injured in the crash.

"[The] parents of the child were very distraught on scene," he said.

"They've been assisted by members of the community who've been able to render first aid and then called upon emergency services to give that child the best chance [of survival]."

Neighbour Paula Galvis said she saw emergency vehicles rush to the street.

"We just heard screaming and then five minutes later we heard police cars," she said.

"[I am] so sad, I really can't believe [it], this is a really busy road… there are lot of families here."

The boy is now in a serious but stable condition in the Royal Children's Hospital.

Any witnesses to the collision are urged to contact Crime Stoppers.