Descripción: The main environmental problems existing in Buenos Aires metropolitan area were studied in an area located on the Pampean plains (Llanura Pampeana) at about 32°S and 66°W. Since its foundation in 1580, the city of Buenos Aires has experienced a striking population growth, to its present level of 13,000,000 inhabitants. The main geoenvironmental problems that pose a threat to Buenos Aires population are: flooding, regional rise in the water table, disposal of domestic and industrial waste in land-fill sites, mining dust, expansive soils and contamination of soils, water and air. This paper focuses on the geological, geomorphological and edaphic aspects, which may have controlled the occurrence of these processes. Thematic mapping of the main physical environmental features would appear to be one of the main tools for solving these problems. © 2004 Asociación Geológica Argentina.