We have shown in an earlier work that the addition of both organomodified layered silicates and micrometric calcium carbonate (CaCO3) into a polypropylene (PP) matrix resulted in improved mechanical properties due to synergistic effect of the fillers. In this study, we analyzed the feasibility of producing continuous glass fibers composites with micro/nanoreinforced matrix. In particular, either highly filled matrices with micrometric CaCO3 (22, 40, and 50 wt %) or micro/nanoreinforced matrix were used to prepare composites in order to investigate the effect of fillers on both mechanical and thermomechanical properties. The best mechanical performances were obtained when nano- and microsized particles were combined to reinforce the thermoplastic matrices employed in the film stacking manufacturing method. In such systems, the micro/nanocomposites have improved the flexural properties of the continuous fiber laminate, producing an increase of both flexural modulus (60%) and flexural strength (130%). Moreover, storage modulus of glass fibers composite prepared with micro/nanoreinforced matrix was higher than modulus of the composites manufactured with either neat PP matrix or microreinforced matrix in −40/150°C temperature range.