Background: Vasovagal syncope (VVS) occurs in > 40% of individuals at least once in their lifetime. Sex-dependent differences in presentation and outcomes are not understood. Objective: To study the cause of syncope in young Egyptian Population with inconclusive holter monitoring results. Patients and Methods: The present study enrolled 60 patients with unexplained syncope presenting at Cardiology Department, Alexandria Main, UniversityHospital, either as outpatients or during hospitalization. We excluded patients with cardiac or neurologic syncope. All patients were subjected to thorough history taking with special emphasis on important features, physical examination (blood pressure, pulse and complete cardiac examination), standard 12 lead emergency electrocardiography (ECG) for evidence of abnormalities suggestive of arrhythmic syncope, calculations of OESIL (Osservatorio Epidemiologico sulla Sincope nel Lazio) risk score (ORS), conventional transthoracic echocardiography for confirmation of exclusion of definitive structural heart diseases, Holter 24 hours for exclude any arrhythmic syncope, and Head-up tilt- table testing. Results: There was a statistically significant difference between the 2 studied groups regarding true syncope (p-value 0.001), frequency of attacks (p-value 0.001), prodromal symptoms (p-value 0.001), duration (p-value 0.006), resting pulse (p-value 0.013), and resting systolic pressure (p-value 0.001). There was no difference regarding recovery (P value = 1), resting diastolic pressure (p-value 0.317) and mean age(Value =0.264).There were statistically significant differences between the 2 studied groups regarding the negative results of head up tilt testing (HUT) test (p-value 0.001), drug free phase (p-value 0.002), pharmacological provocation(p-value 0.001), and the vasodepressor response III (p-value 0.038). The mixed response I was not statistically significant between the 2 groups (p-value 0.754) as well as the cardio inhibition response with IIb or without IIa a systole ( p-value 0.612). Conclusion: Female patients were experiencing syncopal episodes for longer periods of their lives, and more episodes of syncope than male patients