Paul Edden, team leader for the Kamala Police Volunteers, said witnesses told him when he arrived at the scene that the man was crossing the main road in Kamala to go to the ATM at Tesco Lotus.
When he walked back across the road, he was hit by a car. He suffered serious head injuries and was taken to Patong Hospital.
"The injured man was wearing a white shirt, the road was well-illuminated, and there was little traffic. THe car should have avoided him with ease," Mr Edden said.
The driver was being questioned by Kamala police as the investigation continues.