From Manila, cruising along the Old National Highway after taking the South Luzon Expressway’s Muntinglupa (Rizal) Exit, brings you to the first town of Laguna. San Pedro welcomes you with its old historical arch marking the boundary of Rizal and Laguna. During the early Spanish period, this present day industrial town was known as "Tunasan." It used to belong to a widespread territory called Tabuco (end of the river), which extends up to the present day Calamba City.
Tunasan got its name from a medicinal plant, a variety of prickly pears called Tuna. It is an erect, treelike species— Punta Tuna, bearing sweet edible fruits. The plant is a native of Mexico and the West Indies.

      Soon after Salcedo dominated the region, Tunasan became a part of a big track of land King Philip II of Spain awarded to Don Esteban Rodriguez de Guigeroa, known as Adelantado de Mindanao. During the period, the King of Spain awards pieces of land in its dominion called “Encomienda.” to those who have served the king. This entitles the “encomiendero,” the recipient to collect tributes from natives The “Adelantado” caught the attention of the king for overthrowing a big band of bandits in Sulu.

      In 1576, Don Esteban executed his last will and testament granting all his properties in the Philippines and Mexico to his wife. The testament indicated that if his wife will die without leaving natural heirs, all his properties including its proceeds shall go to the establishment of a seminary. This caused the incursion of Augustinian priests to Tunasan. They resided at Don Esteban’s Tunasan Estate.

       Later, Jesuits of Collegio de San Jose joined the Augustinians. They built a chapel they called “Ermita” and dedicated it to St. Peter the Apostle.

       In 1725, by order of the Spanish government, Tunasan separated from Tabuco. Don Esteban Guigeroa’s estate that became a town got the name San .Pedro Tunasan. At the time of its foundation, the Alcalde Mayor appointed an interim Gobernadorcillo. The barrios of Cuyab, San Antonio, Landayan and Poblacion comprised the new San Pedro Tunasan, each one having its own “Cabeza de Barangay (Village Chief).”

      In 1762, King Charles II of Spain relieved the Jesuits from the administration of the Tunasan estate. The estate could have been sold by public auction to the religious orders by the king, like the haciendas in Calamba.

      Later in 1812 and 1880, San Vicente and San Roque joined to be San Pedro’s barrios and then Estrella, Langgam, Laram and Bagong Silang joined-in in 1914 to 1917. The latest addition was Nueva, which was established only in 1973.

      During the American Regime, on January 1, 1903, when the federal government clustered towns for more efficient administrative control, Binan integrated San Pedro. However, four years later, San Pedro regained its township.