Delamination progressive in carbon nanotubes reinforced composites under applied Short Beam Shear test was studied. Experimental characterization was carried out using ASTM D2344 standard norms for different carbon nanotubes mass fractions ranging from 0 to 4%. Failure modes and the delamination were experimentally characterized by scanning electron microscopy and Kayence microscopy to assess the failure behavior. The numerical model was created under ABAQUS software based on the cohesive zone models. The numerical model was formulated according to the damage mechanics. In these models, the cohesive interaction was implanted between elements of each fabric ply to control the initiation and the propagation of the delamination for different carbon nanotubes fractions. The force–displacement curves vs. carbon nanotubes added were obtained for the numerical model and shown to be in good agreement with the experimental data. The effect of carbon nanotubes on the progressive delamination was elucidated.