Abstract : This peer group review meeting of respiratory quantitative fit test (QNFT) methods intended to consider (1) the advantages and disadvantages of presently used fit test methods, (2) the applicability of present methods to field effectiveness measurements, (3) improved methods for determining leakage of respirators, and (4) other research needs to put the field of respiratory protection on a firmer scientific footing. Both instrumentation and methodology were considered in presentations, discussions and workshop sessions as important components of fit test measurement. An important concept enumerated early in the meeting was that fit tests serve several functions (such as research, evaluation, certification, point-of-issue, or field performance) and that specific appropriate methods should apply to each need. Keywords: Quantitative fit test, Aerosol test method, Vapor test method, Protective masks.