A simple method for obtaining an active preparation of IgA-specific protease from a bacterial source is presented. In this method Streptococcus sanguis was inoculated onto the surface of a dialysis membrane on nutrient agar. Following growth, the membrane was removed from the agar surface and washed in a small volume of buffer. A solution with protease activity against IgA1 monoclonal proteins was obtained by clarification of the wash and appeared to be similar to enzyme preparations obtained by other methods.