We report trace gas measurements made both inside and outside the Kuwait oil-fire smoke plume during a flight of an instrumental research aircraft on May 30, 1991. Concentrations of SO2, CO, and NOx averaged vertically and horizontally throughout the plume 80 km downwind of Kuwait City were 106, 127, and 9.1 parts per billion by volume (ppbv), respectively, above background concentrations. With the exception of SO2, trace gas concentrations were far below typical U.S. urban levels and primary national ambient air quality standards. Ambient ozone was titrated by NO in the dark, dense core of the smoke plume close to the fires, and photochemical ozone production was limited to the diffuse edge of the plume. Photochemical O3 production was noted throughout the plume a distance of 160 km downwind of Kuwait City, and averaged 2.3 ppbv per hour during the first 3 hours of transport. Little additional photochemical production was noted at a downwind range of 340 km. The fluxes of sulfur dioxide, carbon monoxide, and reactive nitrogen from the roughly 520 fires still burning on May 30, 1991 are estimated at 1.4¿107 kg SO2/d, 6.9¿106 kg CO/d, and 2.7¿105 kg N/d, respectively. Generally low concentrations of CO and NOx indicate that the combustion was efficient and occurred at low temperatures. Low total nonmethane hydrocarbon concentrations suggest that the volatile components of the petroleum were burned efficiently. ¿ American Geophysical Union 1992