The growth charts of basic body measurements are an important aid for the daily routine practice of paediatricians. Charts for children from birth to 2 years of age form an integral component of a set of such tools for the age spectrum from birth to 18 years of age. The interpretation of growth charts is highly dependent on the data on basis of which the charts were constructed. In the Czech Republic, the growth reference data have been regularly updated since 1951, in 10-year intervals. These updates are based on data from nation-wide anthropological surveys of children and adolescents. Countries, which do not have their own reference data, have been using for growth assessment the 1977 World Health Organization (WHO) and the National Center for Health Statistics (NCHS) international reference growth charts. These charts, developed for height for age, weight for age, and weight for height, were based for children younger than 2 years on a longitudinal study of North American children. Over the years, use in practice showed that because of the original criteria used to select the child population studied, these reference growth charts were not suitable for assessing growth of breastfed children. The 1977 reference is based on predominantly artificially, that is formula-fed, child population. The evidence shows that breastfed and artificially fed infants grow differently and that the growth pattern of breastfed children most likely better reflects physiological growth. In 1994, based on the accumulated evidence, the WHO started working on new international standards which would be based on a sample of healthy breastfed children. The project, the WHO Multicentre Growth Reference Study (MGRS), was carried out from 1997-2003. It focused on collection of growth and development data of 8440 children from different ethnic and cultural groups. The underlying assumption of the project was that in favourable socio-economic conditions and with a recommended level of nutrition and lack of maternal smoking, children's growth is very similar, regardless of their ethnic origin and geographic location. The new growth standard for children 0-5 years of age will be available early in 2006. In the Czech Republic, we plan to analyse our national reference against this standard. If considered necessary, a process will be put in place for replacing the Czech reference with the WHO standard. The objective of this article is to alert health professionals that growth charts currently used in their country may not represent an optimal tool, especially with regard to the assessment of nutritional status for 0 to 2-year-old children, unless already based on data of breastfed children. Generally, the lack of awareness of the difference between the two growth patterns--the breastfed versus artificially fed child--poses a serious problem since a strict interpretation of the growth charts may lead to early supplementation of breastmilk with infant formula and/or premature introduction of complementary foods. Both of these practices tend to lead to premature cessation of breastfeeding, one of the key strategies to improve child health and development.