Growth standards are important for the assessment of growth in children. It is well known that the growth of children is affected by a combination of genetic and environmental factors. Secular changes in height for age values are also known to affect the timing of puberty and brain weight. Different populations may be at different stages of this secular trend. It is therefore necessary to periodically update the growth standards for each population to identify these changes. Growth standards for Turkish children from birth to 5 years and also for children between 6 and 18 years were recently updated. The growth data on infants and young children, reviewed in this chapter, were based on height/length, weight, and head circumference measurements of 2391 boys and 2102 girls from a Well-Child Clinic. The LMS method was used for the analyses. The percentage of exclusive breastfeeding was 62% at 4 months and 26.6% at 6 months in this population. The continuation rate of breastfeeding at 12 months was 62.5%. Comparison of new standards with previous Turkish data showed an increase in height of 0.9 cm for boys and 1.1 cm for girls at age 5 years. The increase in weight was 0.220 kg in girls, while a decrease of 0.160 kg was noted in boys. Comparison with the 2000 US, Swedish and the recent WHO Growth standards indicated that population differences may exist in pre-pubertal years especially in head circumference values.