A burglar attacked his victim after she found him ransacking her house.
The 62-year-old woman was confronted by the man after she arrived home on Rawdon Road, Rawdon, Leeds.
He punched her in the face before escaping with jewellery.
Det Con Sam Warburton, of Leeds CID, said: “This was a serious incident in which a 62-year-old woman was assaulted in her own home in a cowardly and thuggish assault.
“The victim has quite understandably been very upset by the incident and we are appealing for assistance from the public to catch this man.”
The incident happened at about 10.10am on April 9.
Anyone with information should call CID on 101.