The Knoevenagel reaction is easily carried out without a solvent in the presence of the fluorapatite (FAP) alone, activated by water, benzyltriethylammonium chloride (BTEAC) and both. The role of water is clearly shown. The FAP activated with water and the ammonium salt is an excellent catalyst of the Knoevenagel condensation, leading to excellent yields in a few minutes.