Recreational use of synthetic cannabinoids (SCs), also known as "K2" or "Spice," is becoming a major public-health concern due to their potential for abuse and harmful consequences. New substances are constantly being added to the content of SCs. The dearth of information on these newly added contents as they are introduced into the black market hinders risk assessments of these compounds. We report a highly unusual case of gross hematuria in a 28-year-old male patient after SC use. He was found to have a supratherapeutic INR with no history of prior anticoagulation. His hematuria resolved after four units of fresh-frozen plasma were administered. We include a literature review of the clinical effects of SCs and their possible mechanism of gross hematuria and management.