The incident happened at a property on Lodore Road on Saturday (January 4) at around 6.15pm.
A spokesperson for Nottinghamshire Police said: “It was reported that the offenders have pretended to be police officers and pushed their way inside the address.
“A large amount of cash was stolen and the offenders have made off.”
Anyone who saw the incident or has any CCTV or dashcam footage which may help with the investigation is urged to call Nottinghamshire Police on 101, quoting incident number 661 of January 4 2020.
You can also call Crimestoppers anonymously on 0800 555 111.
In light of the incident, the force has issued a warning to residents in the town, urging them to be vigilant.
The spokesperson added: “If you receive a visit from someone purporting to be a police officer, ask to see their identification card.
“All police officers whether in uniform or not carry identification. You can always phone 101 to check the officer’s credentials.
“We would ask residents in Worksop to be vigilant, challenge anyone who comes without an appointment to your home.
“Please ensure this advice is passed onto elderly relatives they may care for and to look out for elderly neighbours.
“Please also report any suspicious incidents to the police immediately.”