A women was robbed by hoodies while collecting the takings from The Gate Cinema in Notting Hill Gate in broad daylight.
The worker, an employee of a cash in transit company called G4 security, was taking money to a van when the robbers struck.
A man - who is believed to have been wearing goggles over his face - grabbed her from behind and threw her to the ground. Another attacker then grabbed the cash box before escaping south down Farmer Street, Notting Hill.
The thieves, both described as being white and aged about 20, jumped into the back seat of a silver Audi. The car then sped off west down Uxbridge Street.
Detectives are seeking the men involved. The first attacker is said to be about 5ft 6in tall, white and slim, wearing a large grey hooded top. The other man is thought to have worn a dark hooded top, a beige hat and a dark scarf.
Call investigating officer Det Con James Merriman at Barnes Flying Squad on 020 8247 7932 with any information.
