La Laguna's 1st district composed of the province's western municipalities of Alaminos, Bay, Binang, Cabuyao, Calamba, Calauang, Los Baños, Pila, San Pablo, San Pedro Tunasan, and Santa Rosa.

In the immediately preceding gubernatorial election, the Nacionalista Party's Domingo Ordoveza won, but Governor-General William Cameron Forbes, upon the advice of vice governor Newton W. Gilbert, was convinced that Ordoveza bought votes and refused to seat him nor Cailles, and will appoint someone from the Nacionalista Party instead.

[2] La Democracia newspaper had opposed Malvar's appointment, pointing out that he was ineligible for the post as a sitting member of the Philippine Assembly.

[6] A total of two persons ran to fill the vacant seat, namely: Marcos Paulino of the Progresista Party defeated Servillano Platón of the Nacionalistas.

Paulino's win increased the number of opposition Progresistas in the assembly during the 2nd Philippine Legislature.