This paper reviews measurement studies of aircraft cabin air quality conducted between 1985 and 1998. Study results are evaluated in terms of monitoring objectives, sampling design, measurement parameters, data characteristics, quality assurance, level of review, and findings. Monitoring designs ranged from modest efforts involving a handful of flights to extensive efforts involving about 100 flights. Most of the studies reported measurement data for bioaerosols, carbon monoxide (CO), carbon dioxide (CO2) and particulate matter. Formaldehyde, ozone (O3), and volatile organic compounds (VOCs) were measured in fewer studies. Semivolatile organic compounds (SVOCs) were not measured in any of the studies reported in this paper. Average concentrations of bioaerosols and CO were lower than or similar to those encountered in ground-level environments. Average levels of CO2 routinely exceeded the 1000-ppm level, which is often used for judging acceptability of air quality in buildings but may be inappropriate for the cabin environment. Measurement methods used for bioaerosols, CO, and CO2 were found to be reliable. Although concentrations of particulate matter appeared to be low, this finding was not shared by all studies; this is most likely due to variation in the robustness for selected measurement methods, rather than actual differences in concentrations. The paucity of data or inadequacies in methods and instrumentation used for measuring formaldehyde, O3 and VOCs precludes definitive conclusions.