ABSTRACT: The continuous monitoring of cardiac activity using conventional electrocardiography systems restricts signals acquisition to specific locations such as hospitals and medical clinics, and Holters systems don’t transmit the information about the electrocardiogram to the doctor and don’t react if the patient suffers from a cardiac abnormality, they only record the information. Portable remote systems have shown to provide mobility and comfort to the patient by allowing signals acquisition anywhere. This paper shows a remote monitoring system of the cardiac activity capable of performing the acquisition of ECG signals using a smartphone having Android, Bluetooth® communication and 3G technology for processing and visualizing ECG signals. The designed system is battery powered and three electrodes are attached to the patient’s chest to obtain the signals. It was developed a low consumption electronic circuit for acquiring and conditioning these signals using instrumentation and operational amplifiers. The processed ECG signal is then digitalized by an Arduino Nano, and transmitted by Bluetooth from Arduino to the patient’s smartphone so it can be sent to a workstation through 3G technology where the electrocardiogram may be analyzed by a physician. The results obtained on the tests performed validate the developed prototype regarding the acquired ECG signals in the oscilloscope and the developed Android application, which were compared with the ECG signals obtained using a conventional electrocardiography system. The proposed system aims to perform signal acquisition and transmission independent of time and the patient’s location, allow early diagnosis of cardiovascular diseases, reduce the number of the doctor’s visits required, besides providing a device more comfortable to the patient during the monitoring of electrocardiogram signals while performing daily activities.