Fetal exposure to higher levels of PCBs can result in low birth weight and neurological disorders of the newborn. In this study the effects of exposure to the highly toxic dioxins and dibenzofurans, structurally related to PCBs, was investigated in a population of 38 healthy infants. The infants were divided into two groups, according to concentrations of dioxins and dibenzofurans in their mothers milk fat. Neonatal body weight, length, Quetelet index and liver size were determined at different time points during the first half year of life. Additionally neurological development was determined. Comparing these items between the high and low exposure groups did not show any statistically significant differences. The results of this study do not reveal any effect of exposure to background levels of dioxins and dibenzofurans, but in utero exposure to these toxic agents may result in symptoms later in life. Therefore follow-up study of this well defined group will be performed.