We report here a novel comparative study on the structural, morphological, FTIR, optical and photoluminescence (PL) of Zn1-xRExO nanoparticles with RE = Y, La and x (0.00 < x < 0.20). Although the wurtzite structure of x = 0.00, 0.035 samples is free from any secondary lines, some unknown lines could be recorded for x > 0.1 samples. By increasing x up to 0.20, lattice parameters, Zn-O bond lengths, porosity, crystallite size Dhkl, lattice strain and residual stress are increased, but they are higher for a-samples than Y. TEM micrographs of pure and x = 0.10 doped samples consist of nanoparticle agglomerations of irregular grains in different shapes and sizes. The grain sizes (DTEM) obtained from TEM histographs are 180, 330, 460 nm for the pure, Y and La samples, respectively. The addition of RE to ZnO generally shifts FTIR absorption peaks, Debye temperature, and elastic and rigid modulus to higher values, but the shift is higher for La samples than Y. Although the excition energy Ex is almost the same for all samples, the energy gap Eg was increased as x increases to 0.20, but it is higher for La samples than Y. Furthermore, the dielectric lattice constant ЄL, density of charge carriers N and electrical conductivity σele are increased by increasing x to 0.10, followed by a decrease at 0.20. The opposite behavior is true for the interatomic spacing R, dielectric loss, and optical conductivity σopt. The PL intensity shows four continuous well-known peaks visible emissions of near UV, blue, green and red, respectively. Although they are in the same position, their intensities decrease as x increases to 0.20. Interestingly, the intensity of blue emission is greater than that of near UV, such that  [(Iblue/IUV)] > 1]. Moreover, there is another lowest intensity IR emission peak centered at 824 nm (~ 1.507 eV) is obtained for x > 0.10 doped samples. These results are explained in terms of the difference of ionic radii, valence states and generated blocked states between ZnO and RE ions. We strongly recommend the RE doped samples for the applications of optoelectronic and high-power operating devices. To our knowledge, the present systematic investigation probably has never been reported elsewhere, which highlights the present investigation.