Cardiovascular diseases are the leading cause of death in the world. Holter ECG devices that have a great importance in the diagnosis of cardiovascular diseases are simple and useful devices that take the heart signals by non-invasive method. Because of the rapid developments in microcontrollers and Digital Signal Controllers (DSC) capable of real-time signal processing, it is intended that the use of DSC in the devices will create some advantages.Due to the developments of Digital Signal Controllers technology, holter device was preferred to be based on dsPIC by taking the skills of real-time signal processing of these controllers. Secure Digital Card (SDC), Liquid Crystal Display (LCD), Buzzer and Universal Serial Bus (USB) converter circuit were used in the device as peripheral units. It was enabled for patient or those around patient to take precautions by adding device the feature of calculating instant beating during the record in the situations of tachycardia and bradycardia that was possible to take precautions by hearing the aural warning. In addition, a Graphical User Interface (GUI), which provided transferring and processing the data to a computer for the medical specialist, was designed.