Abstarct: 5,6,7,8-Tetrabromo-2,3-dihydro-2,3-bis(2-hydroxyethyl)phthalazine-1,4-dione is synthesized by the reaction of 5,6,7,8-tetrabromo-2,3-dihydrophthalazine-1,4-dione with 2-bromoethanol in the presence of triethylamine. The obtained monomer was polymerized with various diisocyanates such as, hexamethylene diisocyanate (HMDI), tolylene-2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI),1,4-phenylene diisocyanate (p-PDI) and 4,4'-methylenebis (phenyl isocyanate) (MDI) The resultant polyurethanes. Also, 5,6,7,8-tetrabromo-2,3-dihydrophthalazine-1,4-dione was reacted with two diisocyanates: 1,4-phenylene diisocyanate (p-PDI) and 4,4'-methylenebis (phenyl isocyanate) (MDI) leading to new polyureas. The structure of the synthesized polymers were recognized by IR, 1H-NMR spectroscopy methods, viscometery, thermal gravimetric analysis (TGA/DTG) and elemental analysis.