Introduction Pumice particles, which originated from volcanic eruptions centred in the Taupo and Rotorua regions in the North Island, are frequently encountered in many engineering projects. These particles are then mixed with hard-grained materials and deposited as natural pumiceous (NP) sands. Pumice particles are highly crushable and lightweight, leading to difficulty in characterising their properties. The post-liquefaction behaviour of NP sands is important not only for the purpose of investigating liquefaction-induced ground deformation but also for assessing their impact on buried structures, such as pile foundations. This research focuses on the difference between the post-liquefaction behaviour of undisturbed and reconstituted NP sands sourced from Waikato region.