<p>The design of combining carbon/epoxy (CE) reinforcement, multi-walled carbon nanotubes (MWCNTs), and hollow glass microspheres (HGMs) can meet the need for future state-of-the-art materials required in various strata such as aerospace and automotive applications. The effects of HGM content on density, mechanical characteristics, and morphology were explored, and properties were compared with baseline laminate. Unidirectional laminates of carbon epoxy/multi-walled carbon nanotubes/hollow glass microspheres with variable weight percentages using the filament winding technique were fabricated and cured. The amount of MWCNT was held constant (0.1%), while the percentage of HGM was varied from 0.2 to 1% and laminates were prepared. Tensile strength and modulus were found to be decreasing with increase in HGM content at constant MWCNT whereas flexural and short beam shear properties obtained from these tests, respectively, were higher compared to those of the baseline. However, samples with 0.6 weight percent HGM loading with constant MWCNT demonstrated the maximum improvement by 8% in flexural strength and 12% in short beam shear. The fracture surfaces of CE/MWCNT/HGM composite samples were analyzed using scanning electron microscopy technique. The SEM image of the composite shows greater dispersion of MWCNTs in the carbon epoxy matrix, with some agglomerates observed. The increase in HGM content in the formulations resulted in a reduction in density while only slight reduction in mechanical properties, demonstrating that this new scenario may be enforced to replace the CE laminate properties, offering a reasonable weight rebate for these materials.</p> Graphical Abstract <p></p>