In this study, we determined the characteristics of mesospheric wave structures over South Pole Station (90°S) derived from sodium airglow imaging observations. During the winter months of 2003 to 2005 (105 nights), we extracted a total of 768 wave events and separated them into two types (band-type gravity waves and ripples) according to their horizontal wavelengths. The distributions of the observed wave parameters, except for the horizontal propagation directions, were similar to those obtained by imaging observations at other latitudes. The observed gravity waves showed a preference for propagation toward 30°-60°E and 210-240E, whereas the ripples showed a preference for motion toward 90-120E and 300°-330°E. The gravity waves had a weak tendency of being observed in 0100-0700 UT, although the ripples did not show such a time dependence. We also investigated the characteristics of atmospheric instabilities from the alignment of the phase fronts of the observed ripples. Copyright 2011 by the American Geophysical Union.