An intercomparison of total ozone observations made with Solar Backscatter Ultraviolet (SBUV) experiment, the Total Ozone Mapping Spectrometer (TOMS), flown on the Nimbus-7 satellite, and the Dobson spectrophotometer installed at Athens, Greece, is presented in order to examine their precision and accuracy. The results show that there is a very good agreement between the compared datasets corresponding to a regression line coefficient interval of 0.932-0.934. © 1998 Taylor & Francis Ltd.