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The "Fiber Bragg Grating" sensors are, essentially, highly sensitive strain gauge. Their skill to monitor various parameters such as strain, temperature, stress states (and many more under development) has spread out widely their use in many areas. The small size and ease of handling allow their positioning by bonding on existing structures or directly embedding into various materials, in order to create the "smart materials”. Their preventive (precautionary) implementation on materials and structures can provide continuous monitoring of the deformations at several places in order to prevent possible phenomena of failure. Their application on structures in service may allow a monitoring of the phenomena of failure already existing. To get a true, repetitive, measure of parameters that one wants to check it must be ensured an efficient transfer of the deformation from the material/structure to the core of the optical fiber. Considering the structure of the optical fiber, the deformation, applied on the material, is transferred to the sensor through various interfaces. Particularly in the case of embedded optical fibers, the deformation is transferred from the material to the polymer coating (that usually covers the optical fiber), and then from the coating to the optical fiber itself. In case of glued sensors, the strain passes from the material/structure to the glue, from the glue to the cladding, the from the latter to the optical fiber. The purpose of this paper is to evaluate the strength of different types of glue proposed for bonding of sensors.