The main purpose of this thesis was to ensure the quality of rest ECG registration technique. A professional nurse can take an ECG film from a patient. Then the doctor can read the ECG film and make the right diagnosis for the patient´s heart. The written report part and the filmed dvd are the main parts of this thesis. The head topics on the dvd are how to inform a patient about the examination, how to perform the ECG registration and how to analyse the ECG registration. The dvd supports practising and performing clinical ECG registration technique. The thesis justifies and demonstrates how to registrate ECG with high quality. The dvd is copyrights protected.