The [Amb]l-prolinate obtained from the immobilization of l-prolinate anion onto amberlite IRA900OH, was used as a new organocatalyst for the efficient synthesis of 4,4'-(arylmethylene)-bis-(1H-pyrazol-5-ol) derivatives. The prepared heterogeneous organocatalyst was well characterized by using of FTIR, TGA, DTG, XRD and elemental analysis techniques. Short reaction times (5-18 min), excellent yields (82-98 %) and simple experimental procedure with an easy work-up are some of the advantages of the procedure. [GRAPHICS]