Since the 1970s, the World Health Organization (WHO) has recommended the use of the growth references developed by the United States National Center for Health Statistics (NCHS) based on national survey data collected in the 1960s and 1970s. These references are known as the WHO or NCHS/WHO growth references. Over the past three decades, the WHO or NCHS/WHO growth references have played an important role internationally in the assessment of child and adolescent growth and nutritional status. However, the references have a number of weaknesses. The limitations of the infant portion of the references were thoroughly assessed in WHO's effort to develop a new international growth reference for infants and preschool children. The present report discusses the limitations of the NCHS/WHO references for school-aged children and adolescents, including a number of conceptual, methodological, and practical problems. The global obesity epidemic poses another challenge that the NCHS/WHO reference cannot appropriately meet. There is a need for a single international reference to assess the nutritional status and growth of school-aged children and adolescents across different countries.