Measuring the mechanical properties of soft biological tissues in-vitro by using conventional methods (e.g. tension, compression, or indentation) is prone to external testing and sample preparation factors. For example, sample slippage affects the measurement accuracy of mechanical properties of soft biological tissues. In addition, samples have to go through a complex cutting process to be prepared in specific shapes, which increases the post-mortem time spent before testing. The purpose of this study is to investigate the capability of a new technique to measure the mechanics of soft biological tissues without experiencing the conventional challenges. It measures the mechanical behavior of soft materials by introducing and expanding spherical cavity deformations within materials’ internal structure while generating two stresses simultaneously, radial and hoop stresses. Two porcine livers were tested. The experimental data were used to calibrate the material parameters of three hyperelastic models, namely: Yeoh, Arruda-Boyce, and Ogden. Numerical simulations were performed to validate the material parameters. Also, Computed Tomography (CT) imaging technology was used to verify the configuration of the cavity deformations. The outcome of the numerical simulations showed that hyperelastic models were able to predict the material response to cavity loading. In addition, CT imaging confirmed the spherical configuration of the applied deformations. From the experimental results, numerical simulations and the CT imaging, it can be concluded that the cavity expansion test is capable of measuring the mechanics of soft biological tissues without experiencing the difficulties encountered in conventional techniques.