Burglars forced their way into a house in Langley Mill through a kitchen window and stole a handbag, cash, bank cards, a bracelet and a games console.
To escape they unlocked the back door of the house on Aldreds Lane and then left the keys in the outside of the lock.
The couple who live there were upstairs in bed at the time but heard nothing.
Police say the burglary happened between 11.15pm on Friday, July 29, and 7am on Saturday, July 30.
They don’t know what was used to force open the kitchen window.
Any witnesses or anyone with any information should contact police on 0345 123 3333.