  In this paper we show that if a discrete group $G$ acts properly
isometrically on a discrete space $X$ for which the uniform Roe algebra
$C_u^*(X)$ is exact then $G$ is an exact group. As a corollary, we note that if
the action is cocompact then the following are equivalent: The space $X$ has
Yu's property A; $C^*_u(X)$ is exact; $C_u^*(X)$ is nuclear.
