You can see the customer arguing with the valet before he swings and knocks him out with one blow to the head.
The valet, Rodolfo Rodriguez, was unconscious for several seconds.
The customer, who claimed to be a former police officer, even appears to frisk Rodriguez when he's on the ground.
Rodriguez said the guest didn't want to pay the $18 parking fee.
Staff at Ocean Sky Hotel and Resort are questioning why the guest wasn't arrested.
Police said they didn't see the video until Friday and are investigating.