Uniformly reevaluated Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) total ozone data (1978--1985) are compared with data from ground-based stations during the daily overpasses of the satellite. Existence of a drift between the two systems is identified, showing the TOMS-derived total ozone to be decreasing nonuniformly by an average of about 0.4% per year. After removing the individual monthly biases and using the satellite as a transfer standard, the differences between 92 currently operating stations of the Global Ozone Observing System (GO3OS) are analyzed. About two thirds of all Dobson stations show differences of less than 2%, while only half of the M-83 filter stations fall into this good station category; close to 20% of the Dobson stations and nearly 30% of the filter stations show differences greater than 3%. Several examples of individual station discrepancies are discussed in order to encourage the complete reevaluation of the ground-based ozone record and to forewarn potential users from taking the published ozone data at their face value. ¿ American Geophysical Union 1988