A 66-year-old woman was threatened with a knife during a burglary at her home in Cheltenham.
Police were called to the house in Pittville Crescent Lane on Thursday evening after reports of the robbery.
A police spokesman said the man forced his way into the victim's home and threatened her before stealing her bag containing bank cards and about £100.
"The man escaped onto the back of a motorbike being driven by another person," he said.
The first offender is described as around 6ft tall (1.83m), with short, dark curly hair and wearing dark clothes.
"Anyone who witnessed the robbery or saw the bike being driven off about 6.15pm is asked to contact police or Crimestoppers," the force spokesman added.