Increased prevalence of developmental defects of enamel reported in recent studies suggests the involvement of novel environmental causal factors. Among them, toxicants with endocrine disrupting activity retain our attention for their ability to disrupt tooth development, notably the synthesis of the two main dental tissues, enamel and dentin, submitted to hormonal control. As dental tissue mineralization follows a well-known sequence of events that starts during fetal life and mostly ends 6 years after birth, with enamel being assimilated to a fossil, dental defects can be considered as good markers of exposure to environmental pollutants especially those with endocrine disrupting activity. The cellular effects and mechanisms of action of some of them, including pro-estrogenic and anti-androgenic compounds, are presented here.