ABSTRACTThe low-velocity impact studies to account for the variation in the number of basalt fiber layers in the through-thickness loading performance of natural fibre reinforced polymer composites are very limited. These studies are useful to understand the external and internal failure mechanisms of composites at different thicknesses. In this study, the single and multilayered basalt/polyester composite samples were fabricated, as the number of basalt fibre layers increased gradually from 1 to 9, and then low-velocity impact tests were conducted at a constant impact energy of 12 J. The impact data was measured using the LabVIEW software. Further, full-field failure or damage mechanisms of composite samples were investigated using ultrasonic A, B and C scan techniques. Failure mechanisms observed in tested samples were matrix cracking, fibre breakage, delamination, etc. However, the size and shape of failure mechanisms observed were varying with the increase in the number of layers. Samples that had a smaller number of basalt fibre layers (1–4) failed rapidly due to extensive regions of delamination and the failure mode observed was localised damage with higher regions of delamination. However, samples that had a greater number of basalt fibre layers (5–9) could withstand higher impact loads and failed progressively. The failure mode observed in these samples was mainly distributed damage with lower regions of delamination.