Thirty-two-year-old Luis Pichardo and 28-year-old Ignacio Morales of Melrose Park were arrested Saturday.
Undercover agents say they saw them acting suspiciously at a business in suburban Addison Friday night. Police pulled them over for a traffic violation.
Investigators say a police dog alerted officers to the presence of drugs in their car, and Saturday, a search of their home uncovered 3,700 pounds of marijuana.
Each man could be sentenced to up to 30 years in prison if convicted.