Methylxanthine use in the treatment of apnea of prematurity is well documented. This drug is avoided in patients with aberrant pathways of conduction such as Wolff-Parkinson-White syndrome. In theory, methylxanthines enhance precipitation and exacerbation of tachyarrhythmias to which these patients are predisposed. This article reports a case of Wolff-Parkinson-White syndrome in a preterm neonate with severe apneic episodes in which methylxanthines were used. However, no adverse effects on cardiac rate or rhythm were encountered.