2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/96166We obtain the Plancherel decomposition for a reductive symmetric space in the sense of representation theory. Our starting point is the Plancherel formula for spherical Schwartz functions, obtained in part I (math.RT/0107063). The formula for Schwartz functions involves Eisenstein integrals obtained by a residual calculus. In the present paper we identify these integrals as matrix coefficients of the generalized principal series.60 pages, LaTeX 2e, revised introduction. Accepted by Invent. MathRepresentation Theory22E30, 22E46text