An approach is presented for studying the mechanical behavior of soft biological tissue using the finite‐element method and a general constitutive model. The overall computational approach is used for the analysis of the mechanical behavior of the urinary bladder. Bladder tissue is modeled as a composite material formed by a soft matrix reinforced with preferentially oriented fibers. A procedure for identifying the mechanical properties of the main constituents of the bladder tissue by an inverse method is detailed. The mechanical parameters are used for the numerical simulation of the mechanical behavior of the bladder during filling within the finite‐element method