Officers were called to Brent Road, Stirchley at around 7pm on 19 January after they answered the door to two men who forced their way into the property.
The 71-year-old woman and 81-year-old man were tied up and threatened with knives and were forced to hand over a small quantity of cash, jewellery and bank cards.
Following the robbery, officers have been trawling CCTV and making enquiries and are now appealing to anyone with information to come forward.
Sergeant Toni Holl, from the force’s High Harm Team, said: “This was a particularly vicious attack on a vulnerable couple and we are determined to find those responsible.”
I am appealing to anyone who was in the area at the time and who may have seen anyone acting suspiciously to come forward. They may feel that the information they have is insignificant but it could be key to solving this crime.”
The couple were thankfully unharmed but left very shaken by what must have been a terrifying ordeal.”
The two men are described as white, in their mid to late 20s, one had short dark hair and was described as around 5ft 8ins tall. The second man is believed to have longer hair and around 5ft 6ins tall.
Anyone with information is urged to call Sgt Holl and her team on 101 ext 822 3091. Alternatively they can leave information anonymously by calling Crimestoppers the independent charity on 0800 555 111.