© The Author(s) 2022.This study looked into how artificial aging affected the mechanical behavior of composites made of glass fiber reinforced polymer (GFRP). In this context, GFRP composites were produced by vacuum infusion method and artificially aged in the aging cabinet. Three different composite specimen types were tested. These are unaged samples aged 750 h and aged 1500 h. Three-point bending tests were performed to determine the mechanical properties. The absorbed energies of the samples were determined and the maximum bending stresses were calculated. The maximum contact force and sample displacements were also determined. In addition, the damage areas of the samples were examined optically and the changes that occurred with the aging time were determined. Finally, SEM images were taken to observe the changes in the internal structure of the aging and non-aging samples. According to results, as the sample aged, a decrease was observed in the energy values absorbed by the composite samples. In addition, as the aging time increased, it was determined that there was a spread in the damage area and more visible fiber breaks occurred. The increase in the aging time caused a decrease in the stiffness of the composite specimen, worsened its mechanical properties, and increased matrix damage.