Coronary angiography has long been the only diagnostic tool for the invasive assessment of coronary artery disease. Yet it does not allow establishing the functional severity of epicardial stenoses or vasomotor disorders of the epicardial arteries or coronary microcirculation. Functional tests in the catheterization laboratory have recently emerged as an important adjunct to coronary angiography for providing a comprehensive evaluation of the coronary circulation. In this review, we will describe and interpret the key functional tests used in current clinical practise in different clinical settings. (Circ J 2015; 79: 676–684)