The control and monitoring of tritium are important aspects of the Canadian heavy water based nuclear power program. The development of tritium monitoring in Canada is discussed with particular attention being paid to experience gained at the Chalk River Nuclear Laboratories and at Ontario Hydro CANDU nuclear generating stations. Presently a coordinated tritium monitoring development program is underway to provide improved tritium monitoring instrumentation to meet the identified needs of fission reactors, tritium handling facilities, and fusion reactors. This program is outlined with some particular requirements of fusion reactors being discussed in detail.