An air distribution nozzle and fluidized bed including said nozzle, the nozzle including a gas inlet pipe and an air distribution cap defining a space inbetween them, first air outlet means allowing air to flow from the gas inlet pipe to the space and second outlet means allowing air to flow from said space to the ambient area, wherein said second outlet means has an outer cross section along the outer surface of the cap that varies in its vertical height along its horizontal extension.