A 32-year-old man has had his arm and foot severed after falling from a moving train in the WA Wheatbelt town of Brookton, about 140 kilometres south-east of Perth.

It is believed the man and his brother, 34, were drunk when they climbed into a carriage of the moving bulk freight train as it was passing through the town on Saturday night.

The Brookton man fell between the break in carriages and was run over by the train, which severed one of his feet and one of his arms, police said.

His brother made his way across to the other side of the tracks.

Emergency services were called to the scene and the man was airlifted to Royal Perth Hospital where he is in a stable condition.

Police have urged pedestrians to wait for trains to pass before attempting to cross a railway track.