P wave dispersion (PWD) has been accepted as a predictor for atrial fibrillation (AF) in hypertension and some other cardiac diseases. The aim of this study was to compare the P wave parameters between patients with mild-moderate hypertension and those with hypertensive crises.A total of 48 patients, 24 of who presented to the emergency department with hypertensive urgency and 24 patients who were followed in the cardiology clinic with mild-moderate essential hypertension were included in this study. P wave durations were measured manually by two investigators blinded to data of patients.The maximal duration of P wave (P max) and the PWD were found to be significantly different between groups, being longer in patients with hypertensive urgency (p=0,05 and 0,02; respectively).PWD increases in hypertensive urgency states. Clinical implication of this finding should be addressed with further, prospective studies conducted on larger samples.