The man, a resident of Washington, believed to be in his 60s, was travelling with family who live in New Zealand.
When the train made a scheduled photo stop at 10.40am, in an area known as Arthur's Knob, 32km from Wingatui station and halfway between Hindon and Pukerangi, the man appeared to have fallen head-first on to a siding while climbing from the train, Taieri Gorge Railway operations manager Grant Craig said.
"Public announcements are made on how to exit the carriages, and passengers are told to wait until the train stops. They are told to go down three vertical steps backwards, like a ladder. We presume he went face forward and missed the second step, and has fallen head-first to the ground," Mr Craig said.
The accident happened in an area of the Taieri Gorge with no road access and the man was winched aboard the Otago Regional Rescue Helicopter. A St John spokeswoman said a male patient with moderate injuries was taken to Dunedin Public Hospital.
Mr Craig confirmed the man had head and shoulder injuries.
"You can't wrap passengers in cotton wool . . . We cart about 70,000 people a year and maybe once a year we have an incident like this," he said.
The rail company was contacted by the Department of Labour on Saturday and reported the incident to the New Zealand Transport Agency.
