Abstarct: 4-(Phthalimido-N-yl)-1,2,4-triazolidine-3,5-dione was synthesized by the reaction of 4-amino-1,2,4-triazolidine-3,5-dione with phthalic anhydride in the peresence of tetrabutylammonium bromide. The obtained urazole was polymerized with two diisocyanates: 4,4′-Methylenebis(phenyl isocyanate) (MDI) and 1,4-phenylene diisocyanate (p-PDI). The resultant polyurease were characterized by IR, 1HNMR spectroscopy, viscometery, thermal gravimetric analysis (TGA/DTG) and elemental analysis. Also, 4-(Phthalimido-N-yl)-1,2,4-triazolidine-3,5-dione was polymerized with two diacyl chlorides: succinyl chloride and terphthaloyl chloride. The resultant polyamides were characterized by IR, 1HNMR spectroscopy, viscometery, thermal gravimetric analysis (TGA/DTG) and elemental analysis.