In this paper we present method for finding similarities in a pair of three-dimensional objects. The method involves obtaining Boundary Cubes approximations to the two objects, see [A Boundary Representation Technique for Three-Dimensional Objects]. The Boundary Cubes algorithm is a modification to the well-known Marching Cubes algorithm of Lorensen and Cline [A High Resolution 3D surface Construction Algorithm, Computer Graphics]. Having obtained the approximations we can apply exact and inexact graph-matching algorithms to quantify the similarity between two objects. This paper considers methods for exact and inexact graph matching and provides novel and efficient algorithms for graph matching applied to Boundary Cubes representations.