A 55-year-old man presented to the emergency department (ED) following 2 episodes of typical cardiac chest pain and nonspecific electrocardiogram findings. His serial cardiac marker assays revealed an elevated total creatine kinase (CK) and 2 negative cardiac troponin levels. Because of a high clinical suspicion of acute coronary syndrome, a total creatine kinase MB mass was obtained and found to be elevated. Subsequent cardiac angiography demonstrated a significantly flow-limiting coronary artery lesion, and stenting was performed. This case demonstrates that simultaneous CK and troponin measurements may have utility in selected ED patients with chest pain. The interpretation of discordant CK and troponin levels is discussed.