Postbuckling of a three-hinged rod under conservative compressive force is considered. The equations for the system are nonlinear and possess some interesting symmetry properties. The group theoretic methods provide powerful mathematical tools to model and exploit the symmetry properties of a problem. In this paper the symmetry properties of the three-hinged rod problem are explored, and the use of symmetry groups to reduce the problem size is demonstrated. The equations are solved for typical values of parameters and the results are presented. The symbolic computer software, Mathematica, is used for developing explicit equations and their numerical solution.