Inhalation challenges were performed on a patient who had developed symptoms of metal fume fever, after six years of welding. Vital signs, white blood cell count and differential, nasal smears, chest X-ray, and pulmonary function tests were monitored during each inhalation challenge. There was no significant reaction to methylcholine, or to fumes of zinc, copper, and mild steel. Significant restrictive ventilatory impairment, leucocytosis, fever, and symptoms of metal fume fever were noticed after exposure to fumes of silver solder containing twenty four percent cadmium.