A woman was held up at knifepoint in a robbery as she walked her dog.
The 51-year-old was on Union Walk when she was pushed against a wall by one of two men who approached her.
She told police he was holding a knife and demanded cash.
The woman handed over the money she had and the two men ran off following the incident at 11am on Thursday.
The robber was white, 5ft 7ins tall, aged in his 20s, of medium build, with short, mousey hair. He was wearing a navy hooded top and spoke with a local accent.
His accomplice was similar in appearance and was wearing a black jacket.
Witnesses or anyone with information about the incident should contact Chesterfield CID on 101.