Copeptin, the C-terminal part of the prohormone of vasopressin (AVP), is released together with AVP in stoichiometric concentrations reflecting an individual's stress level. Copeptin has come to be regarded as an important marker for identifying high-risk patients and predicting outcomes in a variety of diseases. It improves the clinical value of commonly used biomarkers and the tools of risk stratification. Elevated AVP activation and higher copeptin concentrations have been previously described in acute systemic disorders. However, the field that could benefit the most from the introduction of copeptin measurements into practice is that of cardiovascular disease. Determination of copeptin level emerges as a fast and reliable method for differential diagnosis, especially in acute coronary syndromes. A particular role in the diagnosis of acute myocardial infarction (AMI) is attributed to the combination of copeptin and troponin. According to available sources, such a combination allows AMI to be ruled out with very high sensitivity and negative predictive value. Moreover, elevated copeptin levels correlate with a worse prognosis and a higher risk of adverse events after AMI, especially in patients who develop heart failure. Some authors suggest that copeptin might be valuable in defining the moment of the introduction of treatment and its monitoring in high-risk patients. The introduction of copeptin into clinical practice might also provide a benefit on a larger scale by suggesting changes in the allocation of financial resources within the health system. Although very promising, further larger trials are required in order to assess the clinical benefits of copeptin in everyday practice and patient care.