Abstract: The invention provides an improved method for preparing foamed gypsum products. The invention can utilize a single mixing chamber and significantly improve the efficiency of foaming agent usage. In the method of the invention the point of insertion of aqueous foam into calcined gypsum slurry is positioned such that the foam is agitated less than the calcined gypsum to thereby minimize destruction of the foam while still uniformly dispersing the foam in the calcined gypsum slurry. This is accomplished, for example, by locating an inlet for foam closer to the discharge outlet of a slurry mixing chamber than the location of the inlet for calcined gypsum or by locating the foam inlet in a discharge conduit connected to the discharge outlet of the slurry mixing chamber.