Synoptic-scale zonal eddies (longitudinal disturbances) confined to polar latitudes in the southern hemisphere (SH) upper stratosphere have been observed in Fourier analyses of temperature measurements from the Limb Infrared Monitor of the Stratosphere (LIMS) experiment during April-May 1979. Eddy activity at 60 ¿S, 1 mb is characterized by a Fourier zonal wavenumber 5 (wavelength~4,000 km) disturbance of amplitude 2--3 K which exhibits intermittent eastward propagation, substantial meridional phase tilt, and little vertical phase tilt. These wave properties, along with evidence of pronounced latitudinal variations in the upper stratosphere zonal wind distribution, suggest that the synoptic-scale modes may arise from a latitudinal wind shear (barotropic) instability of the SH polar jet stream. This analysis apparently represents the first identification of polar upper stratosphere synoptic-scale disturbances from satellite-based information, heretofore only seen in rocketsonde measurements in northern hemisphere (NH) polar regions and also predicted by linear model studies. The ability to discern these disturbances in satellite temperature data sets offers an opportunity for future studies of the interhemispheric and interannual variability of synoptic-scale eddy activity in the stratosphere. However, an unambiguous determination of dominant wavelength and phase speed in such studies will be precluded by the fact that satellite data always will suffer from a certain degree of aliasing if disturbances exist with scales unresolved by the asynoptic satellite sampling.