The site of leakage in a patients with rhinorrhea of various origin may be difficult to identify. The aim of our paper is to evaluate the contribution of cisternography in combination with single photon emission tomography (SPECT) to identify the fistulous track. From 1/1/1992 to 30/11/1997 we studied 20 patients with rhinorrhea posing a challenging diagnostic problem as to identification of the leakage site. Two mls of Indium DTPA (In 111) were injected into the subarachnoid space by the lumbar route. The tracer was followed by planar scintigraphy until it reached the cranial base and subsequently the SPECT acquisition started. A fistula was demonstrated in all of our cases including patients with no active leakage at the time of examination, patients with no bone defects on thin sliced CT scanning or patients with a normal MRI. At surgery the fistulous track was confirmed in all but two cases when a bilateral fistula was operatively identified only on one side. In conclusion whenever a CT scanning fails to demonstrate significant bone defects and MRI does not localize a fistulous track, SPECT cisternography via the lumbar route proved in our experience to be a reliable examination for a precise diagnosis.