Police are searching for 39-year-old Aidan Salmon, who has been missing from Hinds, near Ashburton since Friday.
They are appealing for any information about his whereabouts.
Mr Salmon was reported missing after failing to keep an appointment.
Police and his family are concerned about his safety. Police would like to hear from anyone who has seen Mr Salmon or his car since about 8pm on Friday.
Mr Salmon drives a light blue and silver 1996 Mitsubishi Challenger, with the registration number BCE109.
He is also believed to have a large black dog with him, possibly a Rottweiler.