Familial dysautonomia is a hereditary disease characterized by dysfunction of the sensory and autonomic nervous systems. Studies in patients with familial dysautonomia have shown that abnormal cardiac autonomic denervation might influence repolarization. Autonomic tone also affects atrial conduction parameters and P-wave dispersion, which are predictive of atrial fibrillation.To examine the possible association of familial dysautonomia with abnormal atrial conduction and P-wave dispersion.The study population included 12 patients with familial dysautonomia and age and gender-matched control subjects. All participants underwent a 12-lead electrocardiogram under strict conditions. P-wave lengths and P-wave dispersion were computed from a randomly selected beat and an averaged beat using designated computer software.There were no statistically significant differences between the groups in minimal, maximal and average P-wave duration or P-wave dispersion for a randomly selected beat. P-wave dispersion for an averaged beat was also similar. During 6 months follow-up, no supraventricular arrhythmias were documented in either group.We found that patients with familial dysautonomia had P-wave dispersion parameters not significantly different from those of controls. Further research is required to clarify the effects of dysautonomia on atrial conduction in familial dysautonomia.