Mexican police said two buses collided head-on in the southern state of Chiapas, killing at least 19 people.
Federal police said in a statement that 62 more are injured and several are in critical condition.
The collision happened early Friday, just after midnight, outside the town of Ocozocoautla near the Guatemalan border.
Police said it involved two passenger buses. One was carrying tourists bound for the coastal resort of Huatulco.