Prolonged exposure to methylmercury, mainly present in sea-food products (fish, mollusks and shellfish) produces deep neurotoxic effects. The main purpose of this study is to quantify this risk for French consumers using consumption and contamination data. French consumers likely to be strongly and lastingly exposed to this contaminant are identified according to their age, sex and socio-economical characteristics, so that adapted recommendations to at-risk consumers may be taken. For 2001, we estimate that 6% of children under 3 are high-risk individuals. Furthermore, no children living in a low income household are high-risk consumers.