The synthesis of poly(dihalophenylene oxide)s by solid-state thermal decomposition of manganese phenolate complexes with ethylenediamine ligand was achieved. The complexes were characterized by infrared (IR) spectroscopy and C, H, N elemental analysis. The dependence of the yield of polymers on temperature and decomposition time of the manganese complexes with 2,4,6-trichlorophenol, 2,4,6-tribromophenol and 2,6-dibromo-4-chlorophenol was investigated. The polymers obtained were characterized by H-1 NMR, IR spectroscopy and differential scanning calorimetry and found to be branched. 1,2-Catenation is favoured over 1,4-addition in 2,4,6-tribromophenoxide and 2,6-dibromo-4-chlorophenoxide derived polymers, however, polymers synthesized from trichlorophenolate display a selectivity in favour of 1,2-catenation.