A man has been charged by police over the theft of a car with a three-year-old boy asleep in the back from outside a Perth home.

The boy, who was later found safe in the vehicle at a carpark, was reported missing after the car was stolen from his family's Westminster Street home in East Victoria Park in December last year.

His parents had left the car's engine running behind a closed gate while they unpacked the vehicle.

The theft sparked a huge manhunt in a bid to find the car and child, with police taking the unusual step of sending a text message to more than 250,000 members of the public seeking assistance.

The boy was eventually found inside the vehicle about two hours later after it was dumped in the carpark of a unit complex on Amagh Street, and was returned to his home.

Police said the Serpentine man, 32, was arrested after an "extensive investigation" by Kensington Detectives.

He was charged with stealing a motor vehicle and with committing acts or omissions likely to endanger the life, health or safety of a person.

"It has been established that only one person was involved, and as such we are not looking for any other people," a police spokesman said.

The man is due to appear in Perth Magistrates Court on March 14.