Two solderers exposed to fumes of galvanized metal reported a history of shortness of breath and fever which occurred during the evening and night of days spent at work. Specific inhalation challenges performed by asking subjects to do soldering on galvanized iron revealed a late bronchospastic reaction. One subject also demonstrated a significant increase in oral temperature and peripheral neutrophils. Environmental measurements revealed the presence of zinc after soldering on galvanized metal. This contaminant was not present after a control exposure while soldering on iron. Although metal fume fever has been described in workers exposed to fumes of galvanized metal, this is the first account of occupational asthma due to this agent.