Acting on a tip-off, officials searched the house of Songkran Kaewngern, 32, in Ban Sapung Luang village in Tambon Muangnoi in Pasang district at 7.30am.
Songkran was arrested after 30 meth pills were found hidden in his house.
He said he bought from Latthapol Thikart, a resident of Maetha district in Lamphun for resale.
Authorities later searched the house of Latthapol in Ban Sobmei village in Tambon Thakhumngern and found 45 meth pills.
Latthapol said he bought the drug from a friend in Chiang Mai to resell.