In 2000, the Centers for Disease Control and Prevention (CDC) produced a revised growth reference. This has already been used in different settings outside the USA. Using data obtained during a nutritional survey in Madagascar, we compare results produced by using both the 2000 CDC and the 1978 National Center for Health Statistics (NCHS)/World Health Organization (WHO) growth references. We show that changing the reference has an important impact on nutritional diagnosis. In particular, the prevalence of wasting is greatly increased. This could generate substantial operational and clinical difficulties. We recommend continued use of the 1978 NCHS/WHO reference until release of the new WHO multi-country growth charts.