Association between socio-economic circumstances and children's growth was investigated in a cross-sectional study in preschool children attending nurseries in one district in Prague. Data on socio-economic variables and growth were available for 352 children. In presented analysis, height-for-age percentiles are used as the outcome. Education of mothers was most strongly related to growth in unadjusted analysis. Independent contribution of individual factors was then assessed by logistic regression. After adjustment for birth length, parental height, frequency of illness, housing and car ownership, children of mothers with secondary or lower education had about twice the risk of being in lowest tertile of height-for-age (odds ratio 1.91, 95% CI 0.98-3.70) compared with children of mothers with university education. Paradoxically, children from families without a car had lower risk of delayed growth than those from families with a car (odds ratio 0.52, 95% CI 0.28-0.95). Our results suggest that social environment and behaviour rather than material conditions determine the physical growth of preschool children in Prague 10.