The Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate in ethanol at ambient temperature was catalyzed with range of mono-, meta-and diphosphate complexes. Comparison of the results shows that the catalytic activity of those phosphates is related to the electropositivity of the cation present in the structure and to the availability of the phosphate moiety to serve as a base. (C) 2003 Elsevier Science B.V. All rights reserved.