Authorities say the bag was likely left in the alley sometime Wednesday.
The alley is just east of the Arlington Market shopping center.
Investigators at the Cook County Medical Examiner's office are trying to identify the remains.
Legs found in Arlington Heights alley
April 17, 2010 (ARLINGTON HEIGHTS, Ill.) Police in Arlington Heights were called to an alley to investigate a foul odor Friday night. After arriving, they found the legs of an unidentified male inside a bag.
