A truck hit a car carrying Marmol, a cousin and a friend in his hometown of Bonao near 2 a.m. The All-Star right-hander had just arrived in the Caribbean nation after the Cubs were swept by the Los Angeles Dodgers in the playoffs.
Marmol said in an e-mail to The Associated Press that the air bag deployed and he only suffered a cut and an "inflammation" of his forehead.
"Out of precaution they did different studies on my body, and I don't have any kind of serious injury," he wrote.
A Cubs representative in the Dominican Republic, Jose Serra, said Marmol received seven stitches in his forehead but is otherwise healthy.
Marmol pitched in 82 games this season, going 2-4 with a 2.68 ERA.