Comparisons of total column ozone measurements from three ground-based instruments (Dobson spectrophotometer, ozonesonde, and visible wavelength grating spectrometer) and the TOMS instrument are presented for the period 1991 to 1994 at Arrival Heights/McMurdo, Antarctica. The primary purpose of these comparisons is to investigate the accuracy of the visible spectrometer, while a second aim is to compare version 6 and version 7 TOMS satellite retrievals with the ground-based measurements. While the Dobson, TOMS and ozonesonde measurements show good agreement, there is a seasonal dependence between data from the visible wavelength spectrometer and each of the other three instruments. However, the visible spectrometer produces valuable data for the late autumn and early spring, when data are not available from the Dobson and TOMS. ¿ American Geophysical Union 1996