Fritz Gesztesy, Yuri Latushkin, and Konstantin A. Makarov Evans Functions, Jost Functions, and Fredholm Determinants (200K, LaTeX) ABSTRACT. The principal results of this paper consist of an intrinsic definition of the Evans function in terms of newly introduced generalized matrix-valued Jost solutions for general first-order matrix-valued differential equations on the real line, and a proof of the fact that the Evans function, a finite-dimensional determinant by construction, coincides with a modified Fredholm determinant associated with a Birman-Schwinger-type integral operator up to a nonvanishing factor.