Fractional flow reserve (FFR) is considered the gold standard for functional assessment of coronary stenosis in stable coronary artery disease. The use of FFR enables an ischemia-guided revascularization with improvement of clinical outcomes in a cost-effective fashion. Both clinical and interventional cardiologists should be aware of the advantages and potential pitfalls of this technique. We focus on FFR with the aim to provide the clinical cardiologist with information on indications and technical aspects to confirm a correct execution of FFR in different coronary anatomical settings.