The synthesis of pi-conjugated poly(thiazole-2,4-diyl) (PTz) and its complexes incorporating lanthanide ions in the main chain (PTz Nd3+, PTz-Gd3+) is described for the first time. FT-IR, H-1 NMR, and elemental analysis were used to study the structure of the obtained materials. The magnetic properties of the polymeric complexes were measured as a function of temperature (3-300 K) tinder an applied magnetic field of 30 kOe, and the results indicated that there are ferromagnetic interactions between the metal ions. The complexes PTz-Nd3+ and PTz-Gd3+ have the Curie-Weiss temperature of 254 and 28 K, respectively. Both polymeric complexes exhibited a hysteresis loop at 5 K, the coercive field and remanence magnetization is, respectively, 51.4 Oe and 0.0033 emu/g for PTz-Nd3+; while corresponding values are 26.1 Oe and 0.018 emu/g for gadolinium complex. (C) 2004 Elsevier B.V. All rights reserved.