Trace constituent data are presented from the unique flight of an airliner around the world over both poles. Relatively high resolution and simultaneous measurements of ozone, carbon monoxide, ligh-scattering particles, condensation nuclei, and meteorological parameters were obtained. The mutual variations of the data in the polar stratospheres, and in the tropical upper troposphere, are discussed in their meteorological setting. The data from the Arctic lower stratosphere are consistent with a tropospheric source of condensation nuclei, but not of carbon monoxide. Carbon monoxide mixing ratios in the Antarctic stratosphere averaged 44 ppbv. In the tropical troposphere they averaged 66 ppbv over the Pacific versus 89 ppbv over Africa. A local area of higher concentration (115 ppbv) was encountered over tropical Africal; its possible relation to carbon monoxide production by vegetation and deep convection is discussed. Evidence was found in the tropical upper troposphere of distinct boundaries between air masses of different temperature, ozone content, and particle content.