Teamsters Local 727 filed the suit in federal court, claiming the company unlawfully shut down the facility by violating the WARN act, or the Worker Adjustment and Retraining Notification Act.
The plant at 51st Street and Lowe Avenue in the Back of the Yards neighborhood closed without warning last week.
Some workers said they have been with the company for more than 45 years. The workers said they came to work as normal, and were told the plant was closing and to go home.
PepsiCo said it is complying with the WARN act, and that employees will be paid and benefits will continue for 60 days.
Employees will not be required to work during that period.