A simple method for determination of ammonium in semimicro‐Kjeldahl analysis of soils and plant materials using a Tecator or Technicon 40‐tube block digester is described. It involves use of an inexpensive steam distillation apparatus that permits direct distillation of ammonium from the tubes used for Kjeldahl digestion in 40‐tube block digesters. The method is rapid and precise, and it gives results that agree closely with those obtained by the customary method of ammonium N analysis involving transfer of the Kjeldahl digest before distillation.