This study aims to analyze the competitivity of the cotton production in Brazil and United States of America (USA) in terms of production costs, taking into consideration the 2003/04 crop season. In Brazil, data were colleted in “panel conferences” in the state of Mato Grosso (Campo Novo do Parecis and Pimavera do Leste) and also in the north of the Parana state. USA’s data came from secondary sources. The results showed that Brazil has a better competitivity, with good productivity, but high costs per hectare. The risk of the culture is high, given the short margins and the sunk costs. In USA, the average productivity is smaller than in Brazil; the costs are relatively high and the margins are negative in most regions. Results show that the sustainability of the cotton industry in USA is artificial, and dependent of government support.