The more complex building poses additional challenges to air infiltration measurement, especially in the case of multiple zones and rooms. Today's technology has provided us with a number of measurement choices which include the constant concentration single-tracer gas system, multitracer gas systems using the mass spectrometer, and perfluorocarbon multitracer systems both passive and active. This paper compares simultaneous field measurements in a Princeton-area multifamily building using each of these tracer gas-based air infiltration systems. Personnel from Princeton University, Lawrence Berkeley Laboratory, and Brookhaven National Laboratory were involved in the air infiltration measurement studies. Air infiltration rates in the various zones in each building are compared as well as the ease of implementation of the various approaches in these comprehensive measurements. Sources of errors using the various techniques are discussed.