The purposes of this study were to provide data on the peak VO2 of 12-18-year-old boys from Hong Kong, a densely populated urban environment; to compare these data with those for other similarly aged populations; and to examine the correlations between peak VO2 and various anthropometric parameters of this group. A stratified, random sample of 86 ethnic Chinese boys had their peak VO2 determined using an on-line gas analysis system during incremental, treadmill running. The mean peak VO2 of the boys was 2.7 SD 0.44 l.min-1 or, when expressed in relation to body mass, 52.0 SD 5.8 ml.kg-1.min-1. Peak VO2 (l.min-1) was significantly correlated with body mass (r = 0.72, p < 0.001, age (r = 0.49, p < 0.001) and height (r = 0.71, p = 0.001). Peak VO2 (ml.kg-1.min-1) showed no correlation with age or height. These data suggest that this population group has peak VO2 values very similar to those observed in boys from most other population groups.