Officers patrolling the highway that links Mexico City with the border town of Nogales, Sonora, ordered the vehicle to pull over for a routine check.
The driver, 18-year-old Isaias Rojas Sanchez, displayed “marked nervousness” as he told the police he was hauling cleaning products and air mattresses to Obregon, Sonora.
The officers inspected the truck, finding 39 people under a canvas cover and 20 more in a hidden compartment, the public safety department said.
The 53 men and six women were taken to the main federal police post in Sinaloa, where they received food and medical attention, and will likely be repatriated to Guatemala.
Rojas and a minor who was riding with him in the cab of the truck were handed over to the Attorney General’s Office.
An estimated 300,000 Central Americans undertake the hazardous journey across Mexico each year on their way to the United States. The trek is a dangerous one, with criminals and corrupt Mexican officials preying on the migrants.
Gangs kidnap, exploit and murder migrants, who are often targeted in extortion schemes, Mexican officials say.
Central American migrants follow a long route that first takes them into Chiapas state, which is on the border with Guatemala, walking part of the way or riding aboard freight trains, buses and cargo trucks.