Emergency services were called to Union Street after an 85-year-old was struck by a vehicle.
The crash happened earlier this afternoon, outside Gilcomston South Church.
A nearby shop worker said she saw a man get “knocked down,” while another witness said he was only aware of what happened when he noticed the blue flashing lights.
A police spokeswoman said: “We received a call at 1.15pm in regards to a RTC on Union Street involving a male pedestrian and a vehicle.
“The extent of the man’s injuries are currently not known.”
An ambulance spokesman said :“We received a call at 1.11pm on 17 September 2018 about an incident in Union Street.
“We sent one ambulance and a Paramedic Resource Unit.
“We conveyed an 85-year-old male to Aberdeen Royal Infirmary”.
Emergency vehicles blocked the bus lane in the aftermath of the incident.
Man, 85, struck by vehicle in Aberdeen city centre