Abstract: An improved onepot procedure, which condenses an aldehyde, α,βketoester and urea or thiourea to yield 3,4dihydropyrimidin2(1H)ones/thiones, has been developed by using tetraalkylammoniumstabilized palladium chloride as the catalyst. Experimental results showed that the methodology revealed high catalytic activity for the synthesis of Biginelli reaction products. In this paper, we utilized palladium chloridequaternary ammonium salt (PdCl_2/BTEACl) as a low catalytic loading, homogeneous, neutral, efficient and reusable catalytic system for the Biginelli reaction. This approach appears to be a mild, simple, practical and reusable green process for the preparation of Biginelli products. The catalytic system can be easily separated, and reused for seven times without a considerable change in its activity detected by HPLC.