The men were arrested at a checkpoint set up on Soi Bangthong between 2pm and 4pm, reported Kathu Police.
Soi Bangthong is some 600 metres from the entrance to Kathu Police Station. The street joins the southern side of Phra Baramee Rd, which leads over Patong Hill.
Lt Col Nopparut Sukkree, who was leading the officers at the checkpoint named the two men as Eakkapop Yuyangyun, 39, originally from Nakhon Pathom, and Weerayuth Soontrakul, 33, originally from Pathum Thani.
Mr Eakkapop was found carrying a registered 9mm handgun along with 24 9mm bullets, two magazines and one gun holster.
Mr Weerayuth was found with a registered 9mm handgun, seven 9mm bullets, two magazines and one gun holster.
Both guns were being carried in plastic carry cases, police noted.
Eakkapop and Weerayuth were taken to Kathu Police Station for further questioning, Col Nopparut reported.
Both were changed with carrying a firearm in public without a permit, he added.
The police report gave no indication what the two men explained as their reasons for carrying the weapons in public.