The robberies have all occurred over the past three weeks.
In each of the 11 incidents, polce say the suspect approaches elderly victims, displays a silver firearm and demands the victim's jewelry.
The oldest of the victims was 78 years old.
Investigators have released a surveillance photo of the suspect, who is described as a black male, with a light complexion, approximately 18-25 years-old, 5'2"- 5'5", 150 lbs., with a slim build and was seen wearing a light colored baseball hat.
Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS (8477). The public can also submit tips by logging onto the Crime Stoppers website at http://WWW.NYPDCRIMESTOPPERS.COM or by texting their tips to 274637 (CRIMES) then enter TIP577. All calls are strictly confidential.