The purpose of this study was to compare physical activity levels between white and South Asian children in the UK. The data were obtained from 606, 11-14 year old schoolchildren (397 white; 209 Asian). Physical activity was assessed using the 'four by one day' recall questionnaire from which the time spent in moderate and vigorous physical activity was calculated. Boys were significantly more active than girls (p = .0001), and white children reported significantly greater physical activity than south Asian children (p = .001). Mean +/- SD of time spent in moderate and vigorous activity was 90.2 +/- 65.4 mins and 68.2 +/- 49.3 mins for white and south Asian children and 103.5 +/- 63.4 mins and 65.6 +/- 53.5 mins for boys and girls respectively. These findings indicate that south Asian children are significantly less active than their white peers and there may be a need for specific interventions to target South Asian children particularly.