Background/aim: Juvenile obesity is associated with several metabolic abnormalities, one of them being atherogenic dyslipidemia. Suboptimal fetal growth is associated with obesity risk in childhood, but also with increased rate of metabolic diseases in later life. This study investigated associations of neonatal data (Apgar score, birth weight and birth length) with low-density lipoprotein and high-density lipoprotein (LDL and HDL) subclasses in a group of obese children, as well as a possible impact of breastfeeding duration on obesity-associated lipoprotein subclasses distributions.Materials and methods: We included 42 obese children, aged 14.2 ± 2.1 years. LDL and HDL subfractions were separated by gradient gel electrophoresis and biochemical parameters were assessed by routine methods.Results: Compared with obese children with Apgar ≥ 9, the group with Apgar < 9 had significantly higher percentages of small, dense LDL particles (P < 0.05), due to reduced LDL I (P < 0.01) and increased LDL III subclasses (P < 0.05). Birth weight was positively associated with the proportions of LDL I particles (P < 0.001), whereas birth height positively correlated with the amount of HDL 2b subclasses (P < 0.05). The group of never or less than 3 months breastfed children had significantly smaller LDL size (P < 0.01) and lower proportion of HDL 2a particles (P < 0.05) than their ≥3 months breastfed peers.Conclusion: The results showed significant associations of neonatal characteristics with LDL and HDL particle distributions in obese children. In addition, our results point toward positive aspects of longer breastfeeding duration on lipoprotein particle distributions in obese children.