The article describes the authors opinion about the quality of electrocardiogram (ECG) signal and electrographic events recording by portable wireless system “Spyder”. The morphological features of the ECG signal depending on the location on the chest of the device and its axial orientation were studied. The data of patients with various heart rhythm disorders also were compared (simultaneous registration of the wireless system, “Spyder” and the standard system of ECG Holter monitoring). Highest quality of the ECG signal was observed when the device was located strictly in the middle of the sternum at the level of the 2nd and 3rd intercostal space with the slope of the axis of 30°. The comparison of the data revealed high signal quality, similar morphological picture of both recording systems, as well as a satisfactory quantitative correspondence of events. In general, we can say that the quality of the ECG signal recording and the quality of the analysis of electrographic events by the portable wireless system “Spyder” is quite acceptable for recording and detecting various kinds of heart rhythm disorders. The absence of wires makes the ECG signal stable (almost complete absence of artifacts) throughout the monitoring period.