The aim of this chapter is to focus on the diagnostic procedures used in cardiology. Diagnosis of cardiac diseases is a challenging responsibility of a clinician. Cardiac diseases are usually diagnosed by various laboratory test results and findings from physical examination. Various laboratory tests are performed to patient, to screen the individual risk for cardiovascular disease. The regular cardiovascular health assessment also includes various tests, which help to determine the client’s exposure to the risk factors. Laboratory tests for cardiac disease are complete blood cell count, blood coagulation test, blood urea nitrogen, cardiac enzymes, blood culture, urinalysis, electrocardiography (ECG), continuous ECG monitoring, scintigraphic studies, position emission tomography (PET), echocardiography, transesophageal echocardiography, phonocardiography, cardiac catheterization, radiological studies, and hemodynamic monitoring, which are briefly explained in this chapter.