This paper describes an algorithm for slicing class hierarchies in C++ programs. Given a C++ class hierarchy (a collection of C++ classes and inheritance relations among them) and a program P that uses the hierarchy, the algorithm eliminates from the hierarchy those data members, member functions, classes, and inheritance relations that are unnecessary for ensuring that the semantics of P is maintained.Class slicing is especially useful when the program P is generated from a larger program P’ by a statement slicing algorithm. Such an algorithm eliminates statements that are irrelevant to a set of slicing criteria—program points of particular interest. There has been considerable previous work on statement slicing, and it will not be the concern of this paper. However, the combination of statement slicing and class slicing for C++ has two principal applications: First, class slicing can enhance statement slicing’s utility in program debugging and understanding applications, by eliminating both executable and declarative program components irrelevant to the slicing criteria. Second, the combination of the two slicing algorithms can be used to decrease the space requirements of programs that do not use all the components of a class hierarchy. Such a situation is particularly common in programs that use class libraries.