Editors' Summary: The law surrounding medical monitoring claims is relatively new and unsettled, but the uncertainty of the law has not stopped tort litigants from increasingly asserting such claims when seeking recovery for toxic exposure. This Article analyzes medical monitoring claims and details the difficult issues that courts are struggling with as they determine the viability of such claims. The Article first distinguishes a claim for medical monitoring from similar claims for enhanced risk of harm or fear of developing an injury or disease. The Article next discusses the first cases that recognized and set forth the necessary elements of a medical monitoring claim. From these original cases, recognition of medical monitoring claims quickly spread to other courts, but the issue remained as to the necessity of a present physical injury for a successful claim. A majority of courts now recognize a claim without a present physical injury, but according to the Article a small growing minority of states now require a physical injury. The Article then examines a split among courts as to whether medical monitoring claims qualify for class certification because of the nature of the damages sought. The Article concludes that the disparity of judicial rulings addressing medical monitoring claims indicates an undue stress on the judicial system that should be resolved with litigation.