After stopping at a closed gas station at about 9:30 p.m. near the intersection of Tice Valley Boulevard and Rossmore Parkway, a man stepped outside of his car and was approached by two other men, police said.
The two men forced the victim back into his car, and drove him around for several hours, during which time he was allegedly threatened with a knife and robbed of his cash, police said.
The victim was released in unincorporated Contra Costa County about 1 a.m. when he contacted police.
The suspects fled the area in the victim's car and have not been located.
One suspect is described as a white man, approximately 27 years old, 5 feet 4 inches tall, 165 pounds with short blond hair and a short goatee.
The other suspect is a black man, approximately 34 years old, 6 feet 2 inches tall, 215 pounds with short black hair and wearing a white shirt and blue jeans.
The victim's car is a red 1998 two-door Saturn, with the license plate No.: 5SAT561.
Anyone with information regarding these crimes is asked to contact Walnut Creek Police at (925) 943-5844.