The authors report results of an initial assessment completed during 2008 and 2009 of selected bioaccumulative contaminants in aquatic organisms in six national park units within the Great Lakes Inventory and Monitoring Network. The park units included in the study were Grand Portage National Monument (GRPO), Indiana Dunes National Lakeshore (INDU), Isle Royale National Park (ISRO), Pictured Rocks National Lakeshore (PIRO), Sleeping Bear Dunes National Lakeshore (SLBE), and Voyageurs National Park (VOYA). The principal objectives of this project were (1) to assess spatial patterns in contamination of aquatic biota in the six park units, (2) to identify park units and surface waters where concentrations of bioaccumulative contaminants may pose a risk to organisms atop aquatic food webs, and (3) to evaluate temporal trends in contamination of aquatic food webs in parks of the Great Lakes Network.