From now on, the island's most famous destination will be a safer place, they say.
Talks have been continuing in the weeks since bouncers at one Patong venue were filmed inflicting a savage beating on several young Australian tourists.
The Australians did not go to police out of fears for their own safety but the video, which showed at least two young men being subjected to a savage needless kicking, was viewed widely around the world.
The person who filmed the attack and bravely posted it on Facebook was also intimidated.
Kathu Deputy Superintendent Colonel Akanit Danpitaksat joined the MoU signing and said: ''We all agree that tourists have to feel safe when they visit Patong at night.
''Our police patrols in and around the Soi Bangla walking street are being increased, and the MoU will help to ensure everybody understands the need to uphold the law.''
The brutal attack by the bouncers followed the stabbing death of a bouncer earlier in the year outside another Patong venue.
An Australian expat who stopped to film an eviction from a nightspot with the aim of protecting the people involved became the target for a ''pack attack.''
In fighting for his life, he fatally knifed one assailant.
But police reviewed security camera footage that showed the expat being stomped in the head and dropped a murder charge.
In both the fatal stabbing and the beating by the bouncers, footage of what took place provided conclusive evidence of needless violence by Patong nightspot workers.
The message from yesterday's gathering was clear: under no circumstances should staff at nighttime venues take the law into their own hands.
''Do not attack or beat tourists'' was the first item on the MoU list, followed by ''make sure that the policies regarding tourism in Thailand are fully understood.''
The MoU also made the point that the Patong ''safety zone'' concept of relying on residents and workers to alert and assist police is still seen as the key to tourists feeling safe.
All venues should have security cameras inside and outside, the MoU said.
In other advice, the MoU suggested people should not leave keys in parked motorcycles.
The MoU added that Public Health officials would talk to venues about the need to conform to laws governing alcohol consumption and sales.
The Australians who were beaten by the bouncers said they did not try to avoid paying their bar bill, and produced vouchers that gave them ''special deals.''
The vouchers are now considered to be illegal.
The island's honorary consuls - generally seen as the representatives of tourists and expats - are due to meet with Phuket's Governor to discuss safety and security issues today.