The end of slavery was also the death knell of the monarchy. Since the 1870s the intelligentsia, deeply influenced by French liberalism, had turned against the emperor and agitated for a republic. By the 1880s they had been joined by the officer corps, who blamed Dom Pedro for lack of backing during the Paraguayan war. When the large landowners withdrew their support, furious that the emperor had not prevented emancipation, the monarchy collapsed very suddenly in 1889.

Once again, Brazil managed a bloodless transition. The push came from the army, detachments led by Marechal Deodoro da Fonseca meeting no resistance when they occupied Rio on November 15, 1889. They invited the royal family to remain, but Dom Pedro insisted on exile, boarding a ship to France, where he died in penury two years later in a shabby Parisian hotel. Deodoro, meanwhile, began a Brazilian tradition of ham-fisted military autocracy. Ignoring the clamour for a liberal republic, he declared himself dictator in 1891, but was forced to resign three weeks later when even the army refused to support him. His deputy, Marechal Floriano de Peixoto , took over, but proved even more incompetent; Rio was actually shelled in 1893 by rebellious warships, demanding Peixoto's resignation. Finally, in 1894 popular pressure led to Peixoto stepping down in favour of the first elected civilian president, Prudente de Morais .