Supraventricular Tachycardia (SVT) is one of  the common cardiac arrhythmias. When it occurs during pregnancy it poses a challenge to the treating physician because of the safety concern of the fetus. The basic principle of managing acute  episode of supraventricular  tachycardia in any pregnant woman is same as in nonpregnant and Adenosine is the first line drug therapy. We report here a case of successful cardioversion of Supraventricular Tachycardia with Adenosine in a woman with 33 weeks of pregnancy with ASD secundum and pulmonary hypertension.