Abstract: The purpose of the present study was to examine the effect of height in the predicted VO2max by the Queens Step test among short and tall young girls. A sample of 38 individuals was selected in two stages from a total of 500 individuals and was assigned to two groups of short (n = 20) and tall (n = 18). In order to examine the effect of height in the predicted VO2max, the Queens step protocol and the incremental treadmill speed test were used. Respiratory exchange was measured continuously throughout the test by an automated open-circuit gas analysis system. The study results showed that tall girls revealed a higher VO2max on the Queen`s step and treadmill tests than short girls (Queen`s: 44.09 ± 2.66 vs. 38.96 ± 1.65; Treadmill: 34.03 ± 7.26 vs. 28.15 ± 5.09 mL/kg/min). Based on the obtained findings it can be concluded that the higher VO2max seen in tall girls on the both protocols, may be due to their physiological and physical properties; therefore, it seems that designing of the adjustable steps to the height of subjects for optimizing the estimation of VO2max is not necessary and other physiological factors may be involved, which require further investigation.