The purposes of this study were to assess the natural history of isolated fetal supraventricular tachycardia and to evaluate the role of conservative management without medical therapy in the absence of hemodynamic compromise. Spontaneous resolution of supraventricular tachycardia occurred in eight of nine fetuses followed expectantly with serial evaluations. These data suggest that the spontaneous resolution of isolated fetal supraventricular tachycardia may be a common occurrence. Although conservative management may prove to be a reasonable option for fetuses with isolated supraventricular tachycardia, this approach must be balanced against the lack of reliable predictors for the development of hemodynamic compromise.