An efficient synthesis of hexahydropyrido[2,3-d]pyrimidinetrione derivatives is achieved via tandem Knoevenagel-Michael addition of aromatic aldehydes,methylcyanoacetate and 4(6)-aminouracil in solvent-free conditions in the presence of 10 mol%of ZrO_2 nanoparticles(ZrO_2 NPs) as a heterogenous catalyst.The procedure is formed in high yields,short reaction time and an environmentally friendly specificity. An efficient synthesis of hexahydropyrido [2,3-d] pyrimidinetrione derivatives via tandem Knoevenagel-Michael addition of aromatic aldehydes, methylcyanoacetate and 4 (6) -aminouracil in solvent-free conditions in the presence of 10 mol% ZrO 2 nanoparticles ZrO_2 NPs) as a heterogenous catalyst. The procedure is formed in high yields, short reaction time and an environmentally friendly specificity.