Strengthening and/or upgrading of concrete structures with bonded steel or FRP (Fiber Reinforced Polymers) materials or by use of external tendons have been used for some time. In most cases the bonded on FRP materials are unstressed. However if pre-stressing could be applied better utilization of the strengthening material and a better strengthening result will be achieved. More and more research is carried out in the area of repair and upgrading of concrete structures with pre-stressed FRP materials. External pre-stressed cables of FRP materials have shown to be an alternative to steel cables. Good durability properties and a first-rate behaviour in creep and relaxation have given very good results so far. Bonding pre-stressed FRP laminates or sheets to a concrete surface has proven to be efficient and gives also a better utilization of the strengthening material used. The weak part for both external pre-stressed cables as well as bonded laminates has shown to be anchorage. For cables this is due to lower lateral properties of the cables compared to the axial properties and for laminates due to the high peeling stresses at the cut off end of the laminate Often the anchorage device has problem to handle the high stresses that would justify the use of FRP materials in pre-stressing. However this is changing with a number of research projects around the world focusing on the anchorage issue where a number of anchorage details have been invented Pre-stressed FRP has been proven to be a excellent alternative to pre- stressed steel. At the moment it only lacks more research and field applications to fully be able to use the materials properties.