He was the seventh child of the Caro Rodríguez marriage;[2] among his siblings were José María (1866–1958), the first Chilean cardinal of the Roman Catholic Church,[3] and Francisco Adriano, the eighth Mayor of Pichilemu.

[4] Caro Rodríguez completed his secondary studies at Colegio Santo Tomás de Aquino.

[6] In 1900, he obtained a bachelor's degree in Law and Political Sciences from the same university,[7] and in the following year, he became a graduate in the same faculty.

[10] As a lawyer, he served as acting judge in several communes and departments: Castro Department (16 February – 1 April 1904), Cachapoal (Peumo) (1905), Lontué (1906), San Carlos (1907), Los Andes (1908), Nacimiento (1912), Curicó (Second Court) (1913), Cachapoal (1915), Rancagua (January 1918), and Caupolicán (Rengo) (1920).

[1] Caro Rodríguez became a member of the Conservative Youth of Chile in 1913, and attended that year's convention as a delegate for Rengo.