Este trabalho tem por objetivo fazer uma análise comparativa de materiais compósitos, submetidos aos ensaios de tração uniaxial e flexão em três pontos, compostos com a resina poliéster do tipo teraftálica e fibras de vidro-E, na forma de tecido bidirecional. Through the mechanical tests a comparative evaluation of the behaviour of the mechanical properties such as modulus of elasticity, tensile strength, rupture deformation and maximum stress was carried out. The manufacturing process of the composites was by manual lamination (Hand-layup), using five layers of reinforcement. For the mechanical tests mentioned above, the ASTM 3039 (traction) and ASTM 790 (flexion) standards were followed. It should be noted that for comparison purposes of mechanical properties, part of the specimens were immersed in oil for a period of 365 days (1 year), and another part was exposed to the same period in oil and then exposed to accelerated aging with simultaneous action of temperature and humidity. The accelerated aging was based on ASTM D5427 standard. At the end, the laminates under study, were submitted to the final fracture characterization.