The Schiff condensation of 2-pyridinecarboxaldehyde N-oxide with 2-aminophenol gave a tridentate ligand, abbreviated as Hpoxap. This ligand bears the functionality of a terminating group in a trinuclear complex [Mn(poxap)Mn(ac)(4)Mn(poxap)], where ac(-) is the acetate bridge. The magnetic data were treated simultaneously during the fitting procedure with the spin Hamiltonian containing isotropic exchange, the zero-field splitting parameters, and the molecular-field correction and resulted in J(Mn-Mn)/hc = -4.73 cm(-1), g(Mn(t)) = 1.96, D-Mn(t)/hc = -0.45 cm(-1), and zj/hc = +0.45 cm(-1) with ground state S = (5)/(2), where t = terminal atom. At low temperature, the features of a ferromagnetic correlation become evident.