Authorities say 50-year-old Bruce Sartin Sr. was last seen at his home on the 900 block of Caldwell Corner Road on Thursday.
Police believe he left in his gold 2004 Chevy Silverardo pickup truck. Officers say, due to his medical status, there is a real concern for his welfare.
Sartin is described as a white male, 5'9''tall, 185 pounds, with gray balding hair, blue eyes and a fair complexion.
Anyone with information on his whereabouts is urged to call the New Castle County Police Department at 302-395-8110.