Surname Phayungsak (พยุงศักดิ์ 
, Phayungsak ) , in the world, is a very rare cognomen. The family name Phayungsak is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Predominantly, Phayungsak is the forename as well as the last name.
Siri, Srisamut, Srilapho, Boonjong, Klongyun, Paenkaeo, Pornpatkul, Phuttapim, Punyoyai, Ratsamee, Thepsueb, Sawangkan, Sutthasom, Settamart, Chantapol, Changphet, Chongchap, Patthamat, Tanglukmongkol, Nakpradit, Nilpradub, Waranusat, Sayomporn, Netrung, Janjang, Pongpan, Faji, Unok, Makka, Metha, Saelu, Sapma, Surin, Faggi, Saelio, Srisit, Wongsawat, Buayai, Yindee, Markmee, Sayotha, Saekhow, Athinan, Charika, Chawong, Karamic, Khamong, Khaytuk, Khanom, and Phuangprasert