The City of Pasig (Filipino: Lungsod ng Pasig) is one of the city-municipalities of Metro Manila in the Philippines and was the former capital of the province of Rizal prior to the formation of this grouping of cities designated as the National Capital Region. Located along the eastern border of Metro Manila, Pasig is bordered on the west by Quezon City and Mandaluyong City; to the north by Marikina City; to the south by Makati City, Pateros, and Taguig City; and to the east by Antipolo City, the municipality of Cainta and Taytay in the province of Rizal.
Pasig is primarily residential and industrial but has been becoming increasingly commercial in recent years. Pasig is one of the three municipalities appointed by the diocese of the Roman Catholic Church in the Philippines (as the Roman Catholic Diocese of Pasig), making the Pasig Cathedral (formerly The Immaculate Conception Cathedral) the landmark coincide to its township in 1573.
The name Pasig is believed to come from the Sanskrit word “passis” or sand which refers to the community on the sandy river bank. Some historians trace the name of Pasig to the Tagalog word mabagsik which means violent action which can describe the river which currents brought logs from Montalban to Manila
It was also called “mapaksik” by Chinese in Binondo, Manila. “Mapaksik” later became "Pasik" and then "Pasig". It may also come from "pasigan" which means riverbank.
According to Jose Villa Panganiban, former director of The Institute of National Language, "Pasig" is old Sanskrit meaning “river flowing from one body of water to another,” which briefly describes the river because the river flows from Laguna de Bay to Manila Bay