The self-consistent Ornstein-Zernike approximation (SCOZA) is an advanced microscopic liquid state method that is known to give accurate results in the critical region and for the localization of coexistence curves; this has been confirmed in several applications to continuous and discrete one component systems. In this contribution we present the extension of the SCOZA formalism to the case of a binary symmetric fluid mixture characterized by hard-core potentials with adjacent attractive interactions, given by linear combinations of Yukawa tails. We discuss the stability criteria for such a system and present results for the phase behavior: we recover the well-known three archetypes of phase diagrams, characterized by the different manners the second order demixing line (lambda-line) intersects the first order liquid-vapor coexistence curve. (C) 2003 American Institute of Physics.