More than five million candidates sat the first day of Brazil's national high school exam, the Enem, on Sunday, in one of the largest standardised tests in the world. The National Institute for Educational Studies and Research (Inep) confirmed 5,051,345 registered candidates for the two-day exam, reported to be the highest number since 2021.

On the first day, candidates faced 90 multiple-choice questions covering languages and human sciences, plus a written essay, in a session lasting five hours and 30 minutes. Gates opened at noon and the exam began at 1.30pm Brasilia time. This year's essay asked students to argue for the valuing of Brazil's public health system, the SUS, as a universal right.

President Luiz Inacio Lula da Silva followed the exam from Inep's monitoring room in Brasilia alongside Education Minister Leonardo Barchini. Lula described the operation as a "war for education", saying about 600,000 people were involved in administering the exam across the country so that fairness could be guaranteed.

Inep says it tightened security after leaks and a question-similarity case last year, assembling the tests in a secure room with offline computers, encrypting items on secure drives and delivering sealed packages under escort from the Federal Police and the postal service. The second day of the exam, covering natural sciences and mathematics, takes place on Sunday 15 November. The Enem is the main route into Brazil's public universities through the Sisu, ProUni and Fies programmes, and about 64 percent of this year's candidates are women.