Customs and Border Protection officers in Columbus, New Mexico, carried out a routine check on a Chevrolet pickup.
Officers using an X-ray machine saw the outline of 16 bulky packages stashed in a secret compartment behind the seat.
They initially thought they were packets containing illicit drugs.
"Generally if you see something (with the X-ray machine) you expect it to be narcotics, but this turned out to be cheese," Spokesman Roger Maier said.
The Customs officer did not reveal what kind of cheese it was.