A recently developed method for monitoring biomass burning smoke from space has been applied to measurements over Brazil. Long-term measurements of aerosol index measured from space by a series of satellites show the interannual variability of smoke-covered areas over Brazil. Using a newly developed algorithm, the aerosol index has been inverted into aerosol optical depth values. Coincident ground-based Sun photometer aerosol optical thickness measurements are used to validate this inversion. The interannual variability of the area covered by smoke of varying intensity is described over the period 1978 to 1995. The results show that 1995, the year of the Smoke, Clouds, and Radiation--Brazil (SCAR-B) mission, was similar to recent years for overall smoke area, but the area covered by heavier smoke was larger than other years in the data record. ¿ 1998 American Geophysical Union