 He was the son of Alejandro Montes de Oca, a military officer killed in the Battle of Buena Vista in February 1847, and his wife Guadalupe Saucedo.Montes attended the Colegio de San Juan de Letrán and afterwards courses of physics and botany at the Escuela Nacional de Medicina (currently Faculty of Medicine of the UNAM).In 1856 he began his studies of medicine.