Background: The aim of the study was to analyze the secular trends in height, weight and body mass index (BMI) of children in a Turkish primary school in a 23-year time interval. Methods: The height, weight and BMI of 1099 children between 7 and 15 years old were measured. Data were compared to those of children of the same ages from previous measurements carried out in 1993 (867 children) and in 2003 (1214 children) in the same school. The changes in weight, height and BMI were determined and analyzed statistically. Results: Weight increments between 7.7 and 16.2 kg/23 years and height increments between 1.1 and 8.3 cm/23 years were observed in boys. For girls, weight increments between 6.5 and 13.4 kg/23 years and height increments between 1.3 and 7.2 cm/23 years were indicated. Usually, there were significant height increments between 1993 and 2016 in both genders. However, there were no significant differences in height between 2003 and 2016 for all age groups. Furthermore, there were significant differences in BMI measurements in all age and gender groups between 1993 and 2016. Conclusions: The secular ascending trend in height seems to stop between 2003 and 2016; however, increments in weight and mean BMI tend to continue in Turkish primary school children and adolescents.