In this research, the basic application of ultrasonic wave propagation and velocity measurement in a hyperelastic material is performed both in an experimental sample and a numerical model, in order to develop a methodology for curing quality assessment and defect characterization in polyurethane discs which are used in oil and gas pipeline pigs. A polyurethane cylinder, some density measurement samples and some tensile test specimens have been produced, followed by extracting the tensile specifications from tensile test results and also the density of the specimen through measuring the volume and mass experimentally in Lab. test. Moreover, a through transmission ultrasonic test using a set of longitudinal 120 kHz probes has been performed and wave velocity in the polyurethane specimen has been measured several times experimentally. In order to develop a proper numerical model for further studies on how ultrasound waves are affected by different defects, the hyperelastic material model and Poisson ratio effect on ultrasonic wave features must be studied first. In this research, three material models, including Neo-Hook, Mooney Rivlin and Yoeh have been fitted to the tensile test results, followed by numerical simulation of ultrasonic wave propagation and velocity measurement which are compared with previously described experimental test results. The material model and Poisson ratio outcome on ultrasonic wave velocity have been studied, while other wave features like amplitude and attenuation have not been considered. Finally the results have shown that for the employed polyurethane material, with available density and tensile test results from experimental Lab. test, the Yeoh and Mooney Rivilin hyperelastic models respectively provides more compatible numerical results with the experimentally measured wave speed with errors less than one percent. As it previously mentioned,, performing further studies on the effect of different defects on ultrasound waves based on the results of this study is highly recommended.