Paul Muldownie brandished what he claimed was a needle containing his contaminated blood as he stole cash and other property in raids in central London.
Eventually cornered by three hotel porters, the 24-year-old repeatedly threatened to kill his pursuers with the infected equipment but was overpowered, Southwark Crown Court was told.
James Shaw, for the prosecution, said all the offences occurred on the same day last December.
Muldownie, of no fixed address, who admitted three robberies and asked for two similar counts to be considered, first held up a garage with a knife and stole pounds 80 in Sittingbourne, Kent.
In London he stole more cash from a hairdresser's after warning a frightened assistant that he was an Aids sufferer and had a knife covered with his blood.
He raided on two clothes stores and a hotel gift shop threatening staff with the syringe. After the last incident he was chased and caught.
Nick Doherty, for the defence, said Muldownie, now homeless but who had once lost pounds 60,000 on property deals, only learnt yesterday that he had less than four years to live.
He committed the crimes in an effort to raise money for the Aids charity, the Terrence Higgins Trust.
'He feels a cure has to be found to this disease and he is keen that money is put into research for that purpose,' he said.