The present invention relates to a process for producing of solid particulate olefin polymerisation catalyst or catalyst carrier comprising forming a solution of the catalyst or a catalyst carrier in a solvent, subjecting the solution into an atomization by spraying the solution via a capillary vibrating spray nozzle with a capillary orifice having a diameter of 5 to 100 μm generating a laminar jet of liquid, which disintegrates into liquid droplets entering into the spray-dryer, transforming the droplets with aid of a gas to solid particulate catalyst or carrier in the spray-dryer and recovering the solid particulate olefin polymerisation catalyst or carrier having particle size distribution defined by a volumetric SPAN of 0.7 or less. The invention further relates to the catalyst produced by the methods, and use thereof in olefin polymerisation process.