The Department of National Defence employs a work-related test circuit comprising 10 various firefighting tasks (FF test) to assess the fitness of incumbent Canadian Forces firefighters. The main purpose of this study was to document the oxygen cost of the FF test over a wide range of performance times. These data were then used to predict the oxygen cost associated with the 8 min completion standard. Finally, we examined the influence of gender on selected physiological responses during the FF test. Thirty male and 23 female subjects practiced the test 3-5 times and then completed, in random order and on separate days, a maximal-effort trial while breathing with either a self-contained breathing apparatus (SCBA) or a portable metabolic measurement system (MMC). The breath-by-breath gas exchange data from the MMC were collapsed into a single value that represented the average oxygen cost for each participant to complete the work simulation. To calculate the average VO2 associated with the 8 min completion time, separate regression lines for test duration and average VO2 were generated for males and females. Analyses of covariance (ANCOVA) revealed that the regression lines for the male and female groups coincided, therefore all data were collapsed. The resulting regression equation predicted that the average VO2 associated with the 8 min standard was 34.1 (+/-4.0) mL.kg(-1).min(-1), and this value appears consistent with other research on the oxygen cost of firefighting. There was no evidence to suggest that the oxygen cost of meeting the 8 min standard was different for males or females.