A novel supramolecular complex containing zigzag chain of ethylenediammonium trans-diaquabis(orotato)manganate(II) hydrate (1) has been synthesized and characterized by using IR spectroscopy, thermal analysis (TG, DTG and DTA) and X-ray crystallographic studies. The complex reveals that the Mn(II) atom exhibits a distorted octahedral geometry coordinated by nitrogen and oxygen atoms of two orotate ligands, oxygen atoms of the two aqua ligands. The supramolecular network is constructed by one dimensional novel cyclic dimer zigzag chain, which was further linked by strong hydrogen bonds formed between N and O atoms. (C) 2007 Elsevier Masson SAS. All rights reserved.