Structural monitoring using optical fibre technology may be undertaken to establish the long-term behaviour of structures, components and materials of construction. Condition monitoring may be used in repair and strengthening schedules. The establishment of material durability is also part of the monitoring process. The paper describes the application and development of the use of optical fibres to monitor structures. Examples have been given in which, strain, temperature and moisture content have been determined for structural elements and materials of construction. Of particular interest is the use of an optical fibre system to determine the performance of an actual bridge in Norway, subjected to controlled loading conditions. A further example was the monitoring of tunnel deformations during the construction of a subway system in Tokyo. The results, which have been presented, demonstrate the potential to monitor structures using optical fibres.