Police were searching an area near Somerton last night after a missing man's car was found.
Philip Eyre, 58, was last seen leaving his home in the town at around 5.30pm on Wednesday evening. He was driving a silver Peugeot 206.
Officers said the vehicle was located near the village of Charlton Mackrell yesterday morning.
"We have concerns for the health and wellbeing of Philip Eyre," said Avon and Somerset Police in a statement last night.
"An extensive search is ongoing at the location."
Mr Eyre is described as 6ft 2in tall, with short cropped dark hair and of proportionate build. He usually wears glasses.
Anyone with information should call police on 101.