Analysis of data from the National Study of Health and Growth confirms the need to take age into account when assessing weight-for-height of children aged 5+ to 10+. The method described by Cole leads to errors in the assessment of English and Scottish children, in particular of those tall for their age. This is mainly because the method employs a log(weight)-log(height) rather than a log(weight)-height relationship. Using the latter, weight-for-height centiles are calculated using data for 7157 English boys and girls. It is shown that age last birthday is a precise enough measure of age for the assessment of prepubertal children. Charts of weight-for-height standards are given in an appendix.