Araujo was born in the Hacienda El Condadillo, in the department of Usulután, El Salvador. His family were wealthy landowners who cultivated coffee; his father was of Basque and his mother of Portuguese descent. As a young man he studied medicine at the University of El Salvador, and after earning his doctorate in 1891 at the age of 26, he went to Europe to continue his studies specializing in surgery.
Presidency
Araujo served as the Vice President of Fernando Figueroa from March 1907 to March 1911. At age forty-five, Dr. Araujo stood as an official candidate for national president in the election of November 1910, and won the office with the support of outgoing president Fernando Figueroa. During his presidency, the Army received special attention and increased funding; consequently, many foreign military advisors were hired to educate and train Salvadoran officers. In 1912, Araujo founded the National Guard as a rural police force for the country. Former officers of the Spanish Civil Guard were recruited to train them and to provide men for his private security corps. In a reorganization of the nationaljudicial system, offices of Justices of the Peace were established in all the country's municipalities to ensure the rule of law throughout the nation. A Ministry of Agriculture was formed to promote the cultivation of coffee. In 1911, the Teatro Nacional was built in San Salvador, and the centenary of the independence uprising of 1811 was celebrated with the inauguration of the Monumento a los Próceres de 1811 in Plaza Libertad to memorialize the heroes of the movement. The current national flag and the coat of arms it contains were adopted in 1912.
Death
On 9 February 1913, during a concert in the San Salvador Bolivar Park, President Araujo was severely wounded when farmers Mulatilo Virgilio, Fermin Perez and Fabian Graciano assaulted him with machetes. Araujo died five days later and was buried in one of El Salvador's famous cemeteries. The motives of the attackers, who were executed after a military trial, were never thoroughly investigated.