The study estimated the cost of illness attributable to environmental factors in the city of Manaus between the years 1998 to 2009. The causes of hospitalization were grouped based on studies of the Global Burden of Disease and Comparative Risk Assessment of the World Health Organization. The value was estimated by the sum of (i) hospital spending on treatment of diseases directly attributable to environmental factors, and (ii) the costs of lost workdays resulting from the stay in hospital estimated on the basis of the average earnings of Manaus workers. The data were further calibrated taking into account the coverage of the population with private health insurance. The cost of illness, considering the values corrected by the General Market Price Index for the year 2009 was estimated at R$ 286,852,666.97, of which cardiovascular disease, respiratory infections of the lower airways and diarrheal diseases are responsible for 78.6% of these values. Of the fractions attributable to environmental factors, cardiovascular diseases account for 16% (CI: 7-23%), respiratory infections and respiratory infections of the lower airways for 41% (CI: 32-47%), and diarrhea for 94% (CI: 84-98%) of the global burden of disease.