The annual rate of deforestation in Brazilian Amazonia jumped by an estimated 40% between 2001 and 2002. This increase is in addition to a 15% upward revision by the Brazilian government of the estimated rate for 2001. Examination of the data underlying these estimates and comparisons with other measurements indicates that important questions remain unanswered, especially in the state of Mato Grosso, where assessment of the effectiveness of a deforestation licensing and control programme is critical to future efforts to contain forest destruction. The increase in deforestation rate in Mato Grosso in 2002 (23%) was less than half the increase in the remainder of Brazilian Amazonia (55%), indicating that the state government's deforestation control programme may have had some effect.