The treatment for supraventricular tachycardia in pregnancy is somewhat controversial. Although a variety of medications have been used to terminate this rhythm during pregnancy, all have actual or theoretical drawbacks. Adenosine is a relatively new medication with an extremely short half-life and is effective in the treatment of supraventricular tachycardia. We report a case in which this medication was used successfully during pregnancy. In addition, we found that adenosine had no effect on fetal heart rate in this case.