A heterogeneous, versatile nano-magnesia-zirconia or MgO-ZrO2 (MZ) catalyst was prepared by an ultra dilution method. The as-synthesised catalyst was characterized by several analytical techniques such as XRD, particle size analysis, BET surface area, thermogravimetric analysis (TGA), differential thermal analysis (DTA), FT-IR spectroscopy, SEM (scanning electron microscope), TEM (transmission electron microscope) and XPS (X-ray fluorescence spectroscopy). The surface area is found to be 268 m(2)g(-1). The catalytic activity of MZ was tested for various important organic reactions such as cross-aldol condensation, N-benzyloxycarbonylation of amines, reduction of aromatic nitrocompounds, and synthesis of 1,5-benzodiazepines. It has been observed that for all reactions MZ shows a good catalytic activity. All corresponding products were obtained in good to excellent yield under mild conditions. The MgO-ZrO2 catalyst can be prepared from inexpensive precursors, has high surface area, and is reusable and recyclable for all reactions.