Unilateral cerebrospinal fluid (CSF) rhinorrhea as the only manifestation of the primary empty sella syndrome is a rare event. A case of a middle-aged male patient complaining for intermittent unilateral rhinorrhea, which started 5 months earlier, is reported. The persistence of this state was attributed to an allergic rhinitis. The initial work-up excluded the above diagnosis and an erroneous radiological diagnosis led to a puncture of the left maxillary sinus. A lateral X-ray of the skull and CT scan led to the diagnosis of empty sella syndrome, possibly due to an adenoma or a meningocele.