In the present work, the effect of brine spatial distribution on the electrical resistivity of unconsolidated sands was analyzed. Nine sandpacks were prepared for electrical resistivity measurements using the four-electrode technique. Measurements were carried out during imbibition processes at several saturation levels, where brine was directly injected into the sample at three different injection positions. The results show that the electrical resistivity of sandpacks has a significant dependency on brine spatial distribution. Brine spatial distribution begins to have no significant effect after passing through critical brine saturation, at saturation of 60% -80%. It was also revealed that the sample's grain size contributes to the brine spatial distribution in the pore space. Hence, it affects the measurement of electrical resistivity as well. We also proposed an empirical equation to explain samples that cannot be fitted with Archie's formula properly. The findings should make new insights into physics and important contributions to applied geophysics. © 2021 Elsevier B.V.