Head-up tilt testing potentiated by sublingual nitroglycerin (NTG), advocated by an Italian group, is a simple and safe but still not a standardized, diagnostic tool for the investigation of syncope. In fact, owing to its rapid spread, the original protocol received, often arbitrarily, many subsequent modifications. We now define the best methodology of the test on strictly evidence-based criteria as: stabilization phase of 5 min in the supine position; passive phase of 20 min at a tilt angle of 60 degrees; provocation phase of further 15 min after 400 micrograms NTG sublingual spray. Test interruption is made when the protocol is completed in the absence of symptoms, or there is occurrence of syncope, or occurrence of progressive (> 5 min) orthostatic hypotension. We intend that this protocol, named by us as 'The Italian Protocol', will be accepted as the standard methodology of the tilt test potentiated by sublingual nitrates.