The aim of this work is assessment of fiber orientation in FRC slabs by a multidirectional test. Possibility of obtaining information on the structural contribution of the fibers in the post-cracking behaviour depending on their orientation in the concrete matrix is not only very interesting, but what is more, this is the object of great demand of present civilization. In order to achieve the main goal of this work, the fallowing topics were raised: · Referring to the historical development of fiber reinforced concrete was taken into account all aspects that may have an impact on its development. · Explore knowledge of fibers used to reinforce concrete, particular attention was given plastic fibers. · Fiber orientation as a factor determining the properties of concrete. · Analyse the results of the multidirectional test and determine how the orientation of fibers in the concrete matrix has influenced the results. · Assessment of the results and conclusions.