In 1910 the 80-year-old Díaz decided to hold an election to serve another term as president. He thought he had long since eliminated any serious opposition in Mexico; however, Francisco I. Madero, an academic from a rich family, decided to run against him and quickly gathered popular support, despite Díaz’s putting Madero in jail.

When the official election results were announced, it was declared that Díaz had won reelection almost unanimously, with Madero receiving only a few hundred votes in the entire country. This fraud by the Porfiriato was too blatant for the public to swallow, and riots broke out. Madero prepared a document known as the Plan de San Luis Potosí, in which he called the Mexican people to take their weapons and fight against the government of Porfirio Díaz on November 20, 1910.

This started what is known as the Mexican Revolution (Revolucion Mexicana). Madero was incarcerated in San Antonio, Texas, but his plan took effect in spite of him being in jail. The Federal Army was defeated by the revolutionary forces which were led by, amongst others, Emiliano Zapata in the South, Pancho Villa and Pascual Orozco in the North, and Venustiano Carranza. Porfirio Díaz resigned in 1911 for the "sake of the peace of the nation" and went to exile in France, where he died in 1915.

The revolutionary leaders had many different objectives; revolutionary figures varied from liberals such as Madero to radicals such as Emiliano Zapata and Pancho Villa. As a consequence, it proved very difficult to reach agreement on how to organize the government that emanated from the triumphant revolutionary groups. The result of this was a struggle for the control of Mexico’s government in a conflict that lasted more than twenty years. This period of struggle is usually referred to as part of the Mexican Revolution, although it might also be looked on as a civil war. Presidents Francisco I. Madero (1911), Venustiano Carranza (1920), and former revolutionary leaders Emiliano Zapata (1919) and Pancho Villa (1923) were assassinated during this time, amongst many others.

Following the resignation of Díaz and a brief reactionary interlude, Madero was elected President in 1911. He was ousted and killed in 1913. Venustiano Carranza, a former revolutionary general who became one of the several presidents during this turbulent period, promulgated a new Constitution on February 5, 1917. The Mexican Constitution of 1917 still guides Mexico.

In 1920, Álvaro Obregón became president. He accommodated all elements of Mexican society except the most reactionary clergy and landlords, and successfully catalyzed social liberalization, particularly in curbing the role of the Catholic Church, improving education and taking steps toward instituting women’s civil rights.

While the Mexican revolution and civil war may have subsided after 1920, armed conflicts did not cease, The most widespread conflict of this era was the battle between those favoring a secular society with separation of Church and State and those favoring supremacy of the Roman Catholic Church, which developed into an armed uprising by supporters of the Church that came to be called "la Guerra Cristera."