The objective of this study is to investigate the cost of the use of fire in the Amazon. Burnings are commonplace in the Amazon production process and contribute towards the region's agricultural expansion. Fire is used by farmers in the land preparation process and in clearing forest areas. It also helps combat plants that overrun pastures. However, fire also generates losses for farmers and landowners when it gets out of control. Since the use of fire from a private perspective obeys an economic rationale, the measurement of losses associated to the use of fire must consider the difference between intentional and accidental fires. This study introduces these important concepts which are fundamental to measure the cost of fire. Losses also reach social proportions. To address this issue, we estimated losses related to the release of carbon into the atmosphere, as well as losses due to respiratory ailments provoked by smoke from fires. Our study covered costs related to accidental pasture fires, fence losses, forest losses, carbon emissions, and impacts on human health. Our most conservative estimates indicate an average cost of around 0.2% of the region's GDP during the 1996-1999 period.