The intravenous infusion of ammonium chloride was used to induce ammonia (NH3) poisoning in cattle. A 1.5 M ammonium chloride solution, buffered to pH 7.0, was infused at 400 mL/h until a convulsive episode occurred and therapy was initiated. Convulsions occurred with 200 to 1200 mL of ammonium solution. The clinical picture and metabolic effects were similar to the natural poisoning; no side effected occurred. The hypermmoniemia caused hyperglycemia, hyperlactemia, hyperkalemia and Intense metabolic acidosis. After treatment there was a sharp decrease in plasma NH3. Within 110 min all steers stood and recovered appetites. The induction of NH3 poisoning in cattle with ammonium chloride offers many advantages over the administration of high po doses of urea.