If caught, the man would have been given a $150 instant fine for riding in a dangerous position on a vehicle, Sergeant Ed Baker said.
"He was putting his life at risk.
"He would have been in serious trouble if his clothing had snagged and he was unable to free himself, or if the truck had had to stop suddenly."
Such hitchhikers were not seen often, Sgt Baker said.
"Most people have more brains than this individual."
Police would be interested in hearing from anyone who could identify the man, he said.
The man grabbed hold of the passing Dunedin Carrying Co truck near the skateboard park in Thomas Burns St and travelled about 100m on to Anzac Ave before letting go.
He was with another skateboarder who watched his antic.
Company manager Campbell Gilmore said the truck driver would not have known the man was there.
"It was definitely a dangerous thing to do. He could have been sucked under the truck."
