Abstarct: In this research, we investigated the surface morphology, structural, optical, electrical and thermoelectric properties of CdTe nanostructured thin films synthesized in various conditions by spray pyrolysis method. Here, for characterization of the samples we used: Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), Raman spectroscopy, current-voltage (I-V) characterization, Seebeck effect and ultraviolet-visible (UV-Vis) spectroscopy. The spray precursor is a mixture of two solution: one a 0.04 M cadmium chloride hydrate (CdCl2.H2O) in 25 ml double distilled water and the other a 0.04 M tellurium dioxide (TeO2) in 20 ml ammonia solution, also 2 ml hydrochloric acid (HCl) and 3 ml of hydrazine hydrate were added. In this research, the substrate temperature, precursor volume and the effect of annealing in the presence of nitrogen at two different temperatures were investigated. In general, the FESEM images of the samples showed that all the synthesized samples are contained of compact nano-sized grains (less than 100 nm). From XRD patterns it was revealed that in sample prepared at 350 ºC in addition to unintentional oxide phases is contained of characteristic peaks for CdTe cubic-phase polycrystalline structure with (111) preferential orientation. The annealing process in nitrogen atmosphere showed this process led to diminishing the oxide phases and appearance of relatively pure CdTe cubic-phase polycrystalline structure.