The robbery took place at Embassy Racing on North Moor Road, Huntington at around 8pm on Wednesday (June 3).
The suspects walked into the bookmakers, threatened the staff with undisclosed weapons and stole cash from behind the counter. They were not carrying firearms.
Police say no one was physically injured, but the staff and a customer present at the time were very shaken up by what happened.
Police enquiries are ongoing to trace the suspects.
Anyone who was in the area of Embassy Racing and has any information is asked to contact North Yorkshire Police on 101, select option 2 and ask for the York Serious Crime Team.