A hospital orderly is being hailed a hero after chasing a gunman who held up a Palmerston North dairy.

Englishman Ryan Turner, 23, was having a smoko break when he saw a masked man dash out of the Heretaunga Hospital Store on Wednesday.

"I yelled, 'Oi did you rob the dairy? Stop!'," he later told The Manuwatu Standard.

"I chased him down the road and he turned around and said something, and then pointed something at me.

"I couldn't hear what he said or see what he was pointing, because I'm as blind as a bat and deaf."

Mr Turner said he called police and he later pointed out the man to police officers. He gave himself up when he saw the police car.

Mr Turner said he was told the man had a fake gun in his possession.

"My hands were shaking a bit after, but I was glad I did what I did.

"I can't say I was thinking 100 per cent clearly, I was just acting on instinct."

Word of his heroic actions quickly spread through the hospital, resulting in Mr Turner being nominated for MidCentral Health's "Good Deeds" award.

A 20-year-old man will appear in Palmerston North District Court on June 10 in connection with the robbery.