Cardinal Luis Antonio Tagle led the service at Manila Cathedral at which children between two months and 13 years old were baptised into the Catholic Church.
The service was organised by the Tulay ng Kabataan (TNK) Foundation who said that parents from the slums are often unable to have their children baptised because they cannot afford to travel to a church.
Saturday's service is the fifth time since 2002 that the TNK Foundation has organised a mass baptism in partnership with the Catholic Church.
Cardinal Tagle told the parents and godparents at the mass that baptism "is part of caring and raising a child. Introduce Jesus Christ, how he obeyed God, how he cared for others, how he accepted his fellow man , especially those unloved by society."
After the service, the families were given lunch and sacks of rice.
The TNK Foundation was founded in Manila in 1998.
The foundation has four programmes aiming at giving back the dignity of street children, street children with special needs, scavenger children, and children in slums.