Human anthropometric traits, while significantly determined by genetic factors, are also affected by an individual’s early life environment. An adult’s body height is a valid indicator of their living conditions in childhood. Parental education has been shown to be one of the key covariates of individuals’ health and height, both in childhood and adulthood. Parental functional literacy has been demonstrated to be another important determinant of child health, but this has largely been overlooked in studies on height. The objective of this study was to analyse the associations between parents’ education, their functional literacy and their children’s adult body height. The study used data for 39,240 individuals from the 2016 wave of the nationally representative Life in Transition Survey (LITS) conducted in 34 countries in Southern and Eastern Europe, the Middle East and Central Asia. Using linear and Poisson models, regression adjustment treatment estimators and multilevel mixed-effects linear regressions, the study analysed the links between mother’s and father’s educational attainment, parental functional literacy, measured by the number of books in the childhood home, and children’s adult height. The models also included other individual and contextual covariates of height. The results demonstrated that mother’s educational attainment and parental functional literacy have independent associations with children’s adult body height. Sufficient literacy skills of the parent may have a positive effect on children’s growth even if parental education is low. These associations remained significant across time. The study also provides evidence of a widening of the height gap for men born in the period just before and after systemic transition in post-socialist societies, which may suggest an increase in social differences in early living standards.