AbstractWe establish a discrete-time criteria guaranteeing the existence of an exponential dichotomy in the continuous-time behavior of an abstract evolution family. We prove that an evolution family acting on a Banach space X is uniformly exponentially dichotomic (with respect to its continuous-time behavior) if and only if the corresponding difference equation with the inhomogeneous term from a vector-valued Orlicz sequence space lΦ(ℕ, X) admits a solution in the same lΦ(ℕ, X). The technique of proof effectively eliminates the continuity hypothesis on the evolution family (i.e., we do not assume that U( · , s)x or U(t, · )x is continuous on [s, ∞), and respectively [0, t]). Thus, some known results given by Coffman and Schaffer, Perron, and Ta Li are extended.