Abstract: A rotary mixer and disperser head consisting of a shaft to which is connected a mixing chamber that is to be disposed into a vat or the like for dispersing, dissolving or blending of solids liquids or gasses with other liquids. The mixing chamber has secured to its upper and lower ends a plurality of impeller blades that have an end thereof located outside the mixing chamber to direct material into the mixing chamber and out through openings in the side wall of the mixing chamber during the mixing and dispersing thereof. The shaft for rotating the mixing chamber is merely located at one end thereof and doesn't extend into the mixing chamber and thus does not impede the mixing action taking place therewithin. The specific location of the blades, their relationship relative to the mixing chamber and their configuration provide for a very efficient mixing operation.