Cognomen Lertsak (Lertsak 
) , worldwide, is an extremely rare surname. The last name Lertsak is characteristic of South-eastern Asia, particularly Thailand, where it is an extremely rare surname. Much more prevalently, Lertsak is the forename as well as the last name.
Buwse, Srisamrit, Chingharanon, Chitvarakorn, Poolapanusorn, Rungrochwattana, Jumnongyut, Worasilpchai, Suksawasdi, Seeboonruang, Kumkongsak, Kulvijitrangse, Palasamith, Pengsangtong, Tangpanchasil, Wachiratienchai, Suwannapasri, Songtrakulpisant, Kanjanaruji, Kittisuthiwat, Pakdeechanuan, Prakobchaichana, Supitayakul, Sirikatmaneeratana, Saensurin, Thongyou, Buwsri, Inlao, Ponklin, Jaiman, Noorit, Noonim, Kiemsap, Hongjan, Sansurin, Siangyen, Thongdonnoi, Subuddee, Chenghao, Komchanwong, Khongrit, Kunaruangroj, Panpayak, Pongumpai, Tangwancharoen, Taratham, Thitvirachawat, Thongnoi, Anunboontrick, and Pattanachaikul