The mass was the first of three events marking the event for Chicago's Polish community Sunday.
An afternoon memorial was planned at the Katyn monument in Niles, and a fund-raising dinner was to be held during the evening.
The money raised is to be used for a plaque honoring the victims of the plane crash on April 10 that killed Polish President Lech Kaczynski and 95 others.
The plane was heading to a memorial of the Katyn massacre in Russia.
