In the search of new superconducting materials, some specific structural units are recognized as essential factors for the emergence of superconductivity, such as the CuO₂ planes in cuprates and the Fe-As layers in iron-based superconductors. In this study, we investigate the structural and transport properties of the zinc-based 112-type compound LaZn_1–δSb₂ with Zn-Sb layers at both ambient and high pressures. The LaZn_1–δSb₂ crystallizes in a tetragonal structure with a certain amount of Zn vacancies at ambient pressure. The low-temperature physical properties exhibit paramagnetic metallic behavior, with resistivity showing anisotropy behavior, and the magnetoresistance is positive at low temperatures. Meanwhile, the hole-type Hall coefficient shows significant temperature dependence, indicating that the transport behavior is dominated by multiband effects. Under high pressures, LaZn_1–δSb₂ retains its tetragonal phase while undergoing a volume compression exceeding 25%. As pressure increases, the absolute value of resistance and residual resistance ratio initially decrease and then increase. Further fitting reveals that the transport behavior under pressure remains dominated by electron-phonon scattering and shows almost no pressure dependence. Notably, no superconductivity above 2 K is observed up to the highest pressure of 50.9 GPa in this study. The absence of superconductivity in LaZn_1–δSb₂ may be related to lattice defects induced by Zn vacancies. These results can provide useful insights for the search for new superconductivity in compounds with similar structures.