Lead is the most important cause of environmental pollution, and it is estimated that lead exposure causes 143,000 deaths each year and is responsible for 0.6% of the global disease burden. Lead is a heavy metal widely used in industry, and its toxic effects on the human organism are widely demonstrated, both in organic and inorganic form. The latter is mainly found in occupational contexts and its toxicity is higher because it is more easily absorbed into the human body. This book covers information from two of the largest centers in Buenos Aires, one public and one private, where the clinical and epidemiological characteristics of patients who consulted with a diagnosis of chronic lead poisoning of occupational origin during the period 2005-2014 can be identified.