Background: Exposure to toxic metals remains a public health problem with lifelong impacts on childhood growth and development. We aimed to investigate metals effects on preschool children’ s anthropometric variables. Methods: The study was conducted in Tehran, Iran, from Jul 2013 to Mar 2016. We measured scalp hair metal concentrations (lead, cadmium, arsenic, zinc, manganese, and cobalt), using inductively coupled plasma mass spectrometry, in 207 preschool children’ s (36 to 72 months old). Results: A significant negative correlation between children's hair lead levels and children's weight was found (r= − 0. 178, P<0. 05). Linear regression analysis confirmed the relationship when adjusted for the confounders, including children's age, sex, height, family income, and maternal education (β = − 0. 191; t= − 3. 426, P< 0. 01). The ANOVA analysis showed a significant (P<0. 01) difference between hair lead level and children's weightfor-age percentiles. Totally and separately, in almost all weight percentiles, hair lead levels were higher in girls than boys. Conclusion: The present study on Iranian children showed the current levels of lead exposure might negatively influence on children growth, with higher risk for girls than boys.