Objectives: Environmental pollution is associated with morbidity and mortality for chronic-degenerative diseases. Recent data points out a relationship between proximity to industrial plants and mortality due to neoplasms. The aim of this study has been to compare mortality due to chronic-degenerative diseases in the area of Tuscany (Bassa Val di Cecina), Italy, characterized by the presence of 2 neighboring municipalities similar in terms of size but with substantial differences in industrial activities: Rosignano (the site of chemical, energy production and waste processing industries) and Cecina (with no polluting activity). Material and Methods: Standardized mortality rates for the 2001–2010 decade were calculated; the data of the whole Tuscany was assumed as reference. Environmental levels of pollutants were obtained by databases of the Environmental Protection Agency of Tuscany Region (Agenzia Regionale per la Protezione Ambientale della Toscana – ARPAT). Maximum tolerated pollutant levels set by national laws were assumed as reference. Results: In the whole Bassa Val di Cecina, significantly elevated standardized mortality rates due to mesothelioma, ischemic heart diseases, cerebrovascular diseases and Alzheimer and other degenerative diseases of nervous system were observed. In the municipality of Rosignano, a significant excess of mortality for all these groups of diseases was confirmed. On the contrary, the municipality of Cecina showed only significantly higher mortality rates for ischemic heart diseases. Elevated levels of heavy metals in sea water and of particulate matter which contains particles of diameter ≤ 10 mm (PM₁₀) and ozone in air were detected in Rosignano. Conclusions: This study shows an excess of mortality for chronic-degenerative diseases in the area with elevated concentration of polluting factories. Proximity to industrial plants seems to represent a risk factor for those diseases. Int J Occup Med Environ Health 2017;30(4):641–653