12-Molybdophosphoric acid (MPA) encapsulated in the supercage of dealuminated zeolite Y (DAZY) was prepared and characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential thermal gravimetry (DTG) and atomic absorption spectroscopy (AAS) techniques. The amount of MPA in the supercage of zeolite was 0.0875 g/g of supported catalyst. This catalyst was used for efficient oximation of aldehydes under mechanical stirring, ultrasonic irradiation and solvent-free conditions and the corresponding products were obtained in 65-100% yields. The reaction times were 25-250 min for system under agitation with magnetic stirring, while under ultrasonic irradiation or solvent-free conditions, the oxime yields were increased and the reaction times decreased. The zeolite Y encapsulated 12-molybdophosphoric acid (MPA-DAZY) catalyst was reused several times without loss of its catalytic activity. The amount of Mo leached was less than 2.9%. (C) 2009 Elsevier B.V. All rights reserved.