Abstract: An efficient and environmentally Pumice as a new catalyst for designing of 3,4- dihydropyrimidin-2(1H) ones / thiones via one-pot multi component condensation of aromatic aldehydes, urea/ thiourea and ethyl acetoacetate or acetyl acetone in excellent yields (96-99 %). The advantages using of this new catalyst is very cheap, available, non-toxic, stable under thermal conditions, easy work-up, improved yields, the product of reaction is very pure without using chromatographic methods and solvent free conditions.