The paper summarizes contemporary knowledge and technical possibilities of the use of Holter systems of 24-hour and long-term ECG monitoring in the diagnosis of cardiac arrhythmias. It evaluates the development of different types of equipment and indications for their use. It summarizes the yield of different types and mentions detailed limitations for their use and deals with the economic evaluation of different methods. Finally it summarizes contemporary technical possibilities and future perspectives such as transmission of data over the internet and combination of ECG monitoring with other non-invasive examinations.