The electrophysiological activity of the heart is recorded and presented in form of electrocardiogram (ECG). In 1998 the concept of the P-wave dispersion as the risk factor for atrial fibrillation recurrence was introduced. The presented review aims to prove the P-wave dispersion is an artifact of low accuracy in P-wave measurement, basing on the overview of the publications and the own research in this field. By comparing and contrasting various publications on this topic, the authors observed that it was the imprecise measurement method that resulted in different durations of all P-wave parameters in contrast with the precise measurements. It was indicated that the value of the imprecise P-wave dispersion correlated highly with the maximal P-wave duration measured similarly. In contrast with the imprecise measurement method the minimal and the maximal duration of the P-waves, measured accurately, were almost identical. The studies and the methodological considerations indicate that the P-wave dispersion is a derivative of the imprecise measurement of the ECG recording, inconsistent with the physics rules describing the flow of electric current. The results confirm the authors' observation that the precise measurement of the P-wave makes the phenomenon of dispersion no longer exists. Unfortunately, only a few researchers dare to question the phenomenon of the P-wave dispersion. The discussion should continue, because the P-wave parameters are the data of great importance, as they reflect the dimensions of the atria, electrical conductivity and the condition of the muscle.