Police said they had to taser a woman holding a knife outside a shopping strip in Sydney's inner west.
Witnesses said the woman showed up was armed with a large knife outside a packed café just after 1pm on Sunday afternoon.
The 42-year-old woman was not threatening anyone, but when police arrived and told her to drop the weapon she refused.
Video shows two police moving in to taser the woman, causing her to fall to the ground.
Police said they took action to prevent any harm coming to the public.
The woman did not appear to be harmed by the tasering, but she was taken to Concord Hospital for a mental health assessment.