Pi Sigma Fraternity (ΠΣ) is a national fraternity that is committed to the principles of "Paglingkuran ang Sambayanan" (Service to the Community) and Paragon of Scholarship. Forged at the height of the martial law period, specifically on 15 August 1972, at the University of the Philippines Diliman, the fraternity seeks to contribute to the Filipino people's struggle for a free, just and humane society as well as to carve a fraternity system that is not macho-oriented and rumble-prone.