Going into the 1947 election, the Senate consisted of nine Liberals, 14 Nacionalista, and one Popular Front (Vicente Y. Sotto).

In response, Nacionalista Party President Eulogio Rodriguez appealed for the voters to give the opposition a stronger mandate to fiscalize the administration, which they accused of being corrupt and incompetent.

Two incumbents, all Liberals, defended their seats: Vicente Madrigal and Emiliano Tria Tirona.

There were five neophyte senators, all Liberals: Pablo Ángeles y David, Fernando Lopez, Geronima Pecson, Lorenzo Tañada and Carlos Tan.

Eulogio Rodriguez of the Nacionalistas, was the sole incumbent defeated, but won an electoral protest against Tan and was seated in 1949.