The concentration of five elements considered as potentially dangerous in the world was determined such as: Arsenic, Cadmium, Mercury, Lead and Selenium, for twenty­nine coal seams of the Cesar – Rancheria Basin. The trace elements were determined in the Institute for Combustion Science and Environment Technology, Western Kentucky University, USA. The concentrations of mercury, cadmium and lead in the analyzed coals were found low meanwhile the concentrations of arsenic and selenium were greater. The elements were compared with the average concentrations of coals from United States and China, with world wide averages and the terrestrial crust, they showed that in coals of the basin Cesar Rancheria, the mercury, the cadmium, the selenium and the lead have concentrations smaller than coals of U.S.A. and China, but have concentrations greater than (except the lead) those of the world­wide averages and the terrestrial crust. The arsenic was below the World­wide average and of the United States but it presents greater averages with respect to China and the terrestrial crust. The results could serve to define the possibilities of use and benefit of coals of the basin with the purpose of satisfying the demand of the national and international markets according to the requirements of the international environmental legislations.