Three different bimetallic zinc-cobalt zeolitic imidazolate frameworks (ZIFs) were successfully synthesized at room temperature in water through a green and simple procedure and tested as catalysts for the Knoevenagel condensation reaction between p-Br-benzaldehyde and malononitrile as model reaction. The materials were characterized with various techniques (XRD, ICP-AES, SEM, N-2 adsorption-desorption, TGA) and displayed excellent activities and selectivities. Moreover, the crystalline structure was preserved and the catalysts could be reused at least four times with negligible loss of activity [GRAPHICS] .