  In this paper we explore coarse properties of cusp-decomposable manifolds
first defined by Nguy\^{e}n Phan. We describe the large scale geometry of the
universal cover of a cusp-decomposable manifold and of quasi-isometries between
two such universal covers. This description will provide us the tools to prove
quasi-isometric rigidity for fundamental groups of cusp-decomposable manifolds.
