By virtue of their light weight, high stiffness-to-weight and strength-to-weight ratios, and high resistance to environmental degradation, resulting in lower life-cycle costs, advanced composite materials, commonly known by the acronym FRP, are increasingly being considered for use in civil engineering applications, ranging from the retrofit and rehabilitation of buildings and bridges to the restoration and strengthening of historical, monumental masonry structures. Thanks to the recently published Italian FRP guidelines, CNR-DT 200/2004, by the Italian National Research Council, there has been an increasing demand of their implementation for general strengthening and retrofitting applications as well as seismic mitigation of structures and infrastructures. Besides, the recent earthquake of L’Aquila has decreed their use as the most efficient technological solution for strengthening, repairing, and seismic upgrading of most structural elements in existing buildings, showing also, for the first time, the official implementation of ultra high tensile strength steel fiber sheets. In the following pages, several case studies are reported demonstrating the different fields of applications of the various fibers and technological solutions.