This study compares the air-change rates measured using the decay method with several different tracer gases. The tracer-gas measurements were conducted in a tightly sealed room where constant air-leakage rates, ranging from 0.05 to 1 air changes per hour, could be maintained using an exhaust fan. The tracer gases investigated were CH4, CO, CO2, N2O, and SF6. The agreement between tracer-gas measurements and measured flow rates of the exhaust fan was very good for CH4, CO, and N2O. The agreement was also satisfactory for CO2 and SF6, but the scatter in their data was much greater than it was for the other three gases.