[en] There is an increasing scientific concern that organochlorine compounds, recognized as environmental act through their estrogenic or anti-estrogenic properties. Many endocrine diseases can be concerned by the pathogenic role on environmental residues in their promotion. The carcinogenic potential of environmental xenoestrogens on breast cancer is a matter of controversy. In Europe, despite their prohibition since the 70's, residues persist in soil and rivers, resulting in a widespread contamination of the general population. Our results suggest that environmental exposure to p,p' -DDE, HCB or PCBs may contribute to multifactorial pathogenesis of breast cancer. Male infertility is also a matter of concern. Our data suggest that male infertility can be associated with exposure of the mothers to p,p'-DDE, and that deleterious effects are probably restricted to intra-uterine life. Early or precocious puberty in children adopted from developing countries where organochlorines are still used is frequently reported. A possible relationship with exposure to DDT is suggested. There are two possible pathways to account for precocious puberty following chronic exposure to estrogenic related compounds: weak stimulation of estrogen sensitive tissues or removal in Belgium of the suppressing effects of estrogens on gonadotrophins, suppressing effect that was due to exposure in the country of origin.