The different types of rough equalities [4,5,6] of sets deal with approximate equalities of sets which may not be equal in the usual sense of classical set theory. In this article, we make further study of the properties of rough equalities. A more general kind of equality of sets (we call it rough equivalence) shall be introduced, which captures equalities of sets at a higher level than rough equalities. Many properties of this new notion and its comparison with rough equalities shall be dealt with. We shall make use of the concepts of rough inclusions of sets in this sequel. © 2008 Springer Berlin Heidelberg.