Due to the great differences in knowledge and availability of information on the biodiversity of the different marine regions from Mexico, it was decided to use the opinion of experts for the identification of the high-priority sites for the conservation of the marine biodiversity that includes coasts, the oceans and islands. For this aim, an experts workshop was conducted in October 2005 to determine the marine and coastal high-priority sites for conservation in Mexico. The workshop was organized by CONABIO, CONANP, Pronatura and TNC. After the workshop, the resulting sites were delimited and validated by means of an internet Wiki site, which served like a vestibule for the exchange of information and opinions between the participants. The final product was a map with 105 marine sites.