Postural tachycardia syndrome (PoTS) and vasovagal syncope (VVS) are two prevalent dysautonomic forms of orthostatic intolerance that are linked respectively to a sympathetic hyperactivity and a vagal hyperactivity, but yet, both forms may coexist in the same patient. The mechanism of this association is not well known and the number of published cases remains small to draw management guidelines. We report a case of a healthy 25 years old male who met diagnostic criteria for both PoTS and VVS and who was successfully treated by combining pharmacological and non-pharmacological treatments. We hypothesize through the results of autonomous nervous system (ANS) testing that VVS may be a complication of PoTS through Bezold Jarisch reflex and that the control of PoTS would prevent VVS. Physicians need to be aware of orthostatic intolerance syndromes and resort to ANS tests in patients with a fully normal cardiac workup.