The victim, Narong Jareonpol, 33, was rushed to Patong hospital with a .22 bullet lodged in his head.
Police said he was in his rented room on Petgood Rd, Patong, when he was hit by the bullet fired from a nearby room at about 8:30am.
The shooter fled on a motorcycle but was caught about two hours later near Tritrang Beach. Police seized a CZ .22 rifle and magazine.
The arrested man, 36-year-old Bundit Pramonsil 36, was charged with attempted murder and possession of an unlicensed firearm. He was locked up in Kathu police station.