Structural testing is probably the best and only way to reveal the actual performance of composite laminates, structural components, and complete composite structures under fatigue loading. Nevertheless, the high cost, and the multitude of loading cases a composite structure can face during operation, hinder the possibility of developing methods based solely on experimental results and therefore, theoretical modeling procedures become essential. The complexity of the calculations and model execution for the application of such methods constitutes the implementation of the necessary steps in computer programs indispensable. This chapter presents a state of the art of the existing computational tools for fatigue assessment of composite materials and structures.