Neutral heterotrinuclear complexes 2{[Cu2Ln(H2L)2(NO3)3]}·6CH3OH (Ln = La (1), Nd (2)) and [Cu2Ln(H2L)2(NO3)3]·4CH3OH·2H2O (Ln = Pr (3)) were obtained in the reaction of N,N′-bis(2,3-dihydroxybenzylidene)-1,3-diaminopropane (H4L = C17H18N2O4) with the respective salts of LnIII and CuII. Compounds 1–3 have similar coordination units and display asymmetry in the degree of planarity of the bridging CuO2Ln fragments, which is unusual for CuII–LnIII–CuII complexes. The geometry of the obtained complexes has been compared to the structural data of other 3d–4f–3d trinuclear diphenoxo-bridged complexes. The temperature dependence of the magnetic susceptibility and the field-dependent magnetization indicate that the interaction between CuII and LnIII ions is antiferromagnetic for Ln = Pr (2) and Nd (3), whereas in 1 the CuII–LaIII pairs show no significant interaction, which is in accord with the non-magnetic nature of the ground state for lanthanum(III).