A simple constitutive equation is presented to describe the non-linear load–displacement behavior of the Scapholunate ligament. The model is based on an elastic large strain probabilistic constitutive equation and has been formulated offering three characteristic constants. Experimental data from five human cadaveric Scapholunate ligaments were used to corroborate the accuracy of the model. Good correlation (r2 = 0.90–0.98) was found with the experimental data. Representative characteristic constants for the human Scapholunate ligament based on the model were determined.