Pesticides having a high adverse effect on the health and environment of inhabitants of the Mexican Republic were studied to establish the main parameters to bear in mind for their use and application. The investigation showed that Mexico is the agricultural zone with the highest health damage to its population from pesticides. The valid regulation norms for the use and application of these agrochemicals were analyzed. Case histories recorded by the public health sector in Mexico were reviewed. In this way, a strong relation was found between the health problems and the pesticides applied. Finally, the study concludes that the various Mexican States appear as a risk zone because of contamination by pesticides that are permitted by the regulation norms and by others whose use is prohibited in other countries and in Mexico. This situation causes a serious effect on the health deterioration of people who are exposed to these agro-chemicals and, in some cases, leads to death.