Waist circumference is recommended as a means of identifying people at risk of morbidity associated with central adiposity. Yet, there are no universally agreed cut-points to determine when a waist circumference is too large in young people. In this study we examined the relation between sex- and age-specific waist circumference cut-points, the waist-to-height ratio (WHtR) cut-point of <0.5 and cardiovascular disease (CVD) risk clustering in 164 young people, mean age 14.9+/-0.2 years (mean+/-s.d.). In total 19 (11.6%) of the sample were identified as having CVD risk clustering. These young people were significantly (P<0.001) heavier and had higher body mass index (BMI) and waist circumference z-scores compared to those without CVD risk clustering. The WHtR cut-point of 0.5 estimated CVD risk clustering to a similar extent to sex- and age-adjusted cut-points for waist circumference and BMI. Young people with excess central adiposity (WHtR> or =0.5) were 11 times (OR 11.4, P<0.001), more likely to have CVD risk clustering compared to those who did not have excess central adiposity. The WHtR has several advantages; it is easy to calculate, does not require sex- and age-specific centiles and as has been previously suggested, it is a simple message, easily understood by clinicians and families, to 'keep your waist circumference to less than half your height'.