Two men, with stockings over their heads, broke into the house close to the Hatfield Chase pub, off the A18 Doncaster Road, Hatfield, at 5am yesterday.
They threatened the occupants of the property, leaving the man with a facial injury.
South Yorkshire Police said the victims were left ‘incredibly shaken’.
The robbers escaped with jewellery including a Breitling watch.
A South Yorkshire Police spokesman said: “Officers are keen to hear from anyone who might have seen suspicious activity or a vehicle being driven at speed in the Dunscroft and Hatfield areas of Doncaster.”
Call South Yorkshire Police on 101.