Poly-ether-aroyl-oxadiazoles (PEODZ) of general formula : [GRAPHICS] are reported. Thermal cyclization of the starting polyhydrazides, infrared, thermal, and structural characterization are discussed as function of the number of methylene spacers in the range 2-12. It is found that the position of melting is strongly dependent upon the number of - CH2 -, and that moldable polyoxadiazoles are obtained at x values > 7. The spherulitic nature of PEODZ is clearly revealed by thermal-optical microscopy which, together with isothermal crystallizations at the differential scanning calorimeter, gives a close insight into the crystalline organization of such polymers.