Mexico's top university orders 58,000 students to retake entrance exam amid cheating scandal

In early summer, the National Autonomous University of Mexico administered its first fully remote entrance exam to nearly 160,000 applicants competing for roughly 22,000 spots. The university had made the shift to online testing to reduce barriers for students across the country who would otherwise need to travel to Mexico City, sometimes hundreds of miles, to sit for the exam. It seemed like progress. Then the results arrived, and something was clearly wrong.

The numbers told the story. In previous years, between 2021 and 2025, only 3.5% of test-takers scored 100 or higher on the 120-point scale. This year, that figure jumped to 16%—a more than fourfold increase. The medicine program, one of the most sought-after undergraduate tracks in the region, saw perfect scores climb from 9% of applicants to nearly 30%. These were not marginal shifts. They were the kind of statistical anomalies that suggest something had broken in the system.

The university had deployed what it believed was a robust safeguard: an AI-powered webcam with voice and facial recognition to monitor candidates in real time and flag suspicious behavior. It was not enough. A technical expert who reviewed the results later told the New York Times that roughly half of all exams—approximately 75,000 out of 158,712—likely involved some form of cheating. Test questions had been leaked and sold online while the exam window remained open in May and June. Cheating strategies circulated widely before the test even began. The monitoring system, for all its sophistication, had failed to stop the fraud.

The scandal rippled outward quickly. Mexico's president, Claudia Sheinbaum, suggested that the country's attorney general might need to investigate whether crimes had been committed. The university announced it had filed a criminal complaint and was looking into individuals and companies that allegedly sold fraudulent services to applicants and their families. Just before releasing results publicly, administrators annulled 3,174 exams—about 2% of the total—after detecting identity impersonation, outside assistance, and AI use.

Then came the decision that would affect tens of thousands of students: the university announced that approximately 58,000 applicants would have to retake the entrance exam, this time in person. The rector, Leonardo Lomelí, acknowledged the weight of the decision. "I offer an apology to the candidates who, having been fairly accepted, will be called upon to take the control exam," he said. "However, it is necessary to ensure certainty and guarantee equity in access." The irony was sharp—the move to remote testing had been designed to increase equity, and now the university was forced to abandon it.

Hundreds of students protested in Mexico City on Monday, blocking major thoroughfares in the south of the capital to oppose the requirement to retake the test. The university delayed the academic year start from August 10 to August 31 to accommodate the new exam schedule. For an institution with 115 years of modern history, this was unprecedented: a complete halt to admissions, a technical committee appointed to review the fate of every applicant, and a fundamental reversal of a policy meant to democratize access.

Lomelí framed the decision as an act of institutional responsibility. "The Unam, the home of science, humanities and understanding, knows how to recognize mistakes and self-correct," he said. "There is no evasion or complacency. There is responsibility and we act accordingly." Whether that framing would satisfy 58,000 students forced to sit for another exam remained to be seen. The scandal had exposed not just the vulnerability of remote testing, but the gap between good intentions and the reality of implementation at scale.