Police were called to the hotel, on Rat-U-Thit 200 Pi Rd, at about 1:25pm.
The victim, hotel employee Anuwat Meetham, 33, was reportedly attacked by Chaiyot Weerachue, 37, who also worked at the hotel.
Police said that initial reports indicated that Anuwat fled into the hotel’s front area with Chaiyot in pursuit.
Chaiyot then used an unidentified type of knife to slit Mr Anuwat’s throat before escaping on a grey-and-black Yamaha Aerox motorbike.
Police do have the licence plate number of the motorbike, which was registered in Phuket.
Mr Anuwat was rushed to Patong Hospital where at last report he was in a coma.
Police are reviewing CCTV footage to trace Chaiyot’s escape route to bring him to justice, police said.
It was not reported what may have caused the attack.