A mesothelioma cluster has been found in a remote part of central Mexico. The region is primarily agricultural with no clear source of industrial asbestos exposure. This investigation has revealed that the mesothelioma cluster was situated on an area heavily laden with zeolites. Fibrous erionite was not found. However, the geological conditions and mineralogical characteristics of the affected area very closely resemble those parts of Turkey where mesotheliomas are epidemic and those parts of the western United States where erionite was taken for biological testing. Those biological tests abundantly confirmed the extreme carcinogenicity of erionite for mesothelioma production. This preliminary study should prompt additional investigation to confirm definitively the cause of the elevated mesothelioma risk.