Troop leaders said the robbery happened while scouts and parents from Troop 25778 were unloading and sorting cookies in the 6100-block of West Higgins Road.
Officials said eight cases containing 12 boxes each of Thin Mints were taken, totaling 96 boxes of Thin Mints, worth over $400.
Chicago police have not recovered the cookies. A Girl Scouts spokesperson said the situation was addressed and the missing boxes were replaced, so that the girls' orders could all be fulfilled and the troop will not feel any financial impact.