Using techniques very similar to those used in comparing SBUV total ozone with Dobson [Fleig et al. 1986A>, seven years of total ozone data derived from the TOMS instrument on Nimbus-7 are compared with results from 41 Dobson stations. In this study however, a significant improvement in fit is obtained using a model which assumes a change in the rate of drift between TOMS and Dobson around the middle of 1982. Results indicate that the TOMS measurements have drifted relative to the Dobson stations with a two-part linear trend of -0.25¿0.17% per year during the period from launch to 6/30/82, and -0.51¿0.21% per year during 7/1/82--10/31/85. As discussed in Fleig et al. [1986A>, we are not yet able to definitively separate the causes of this drift between residual uncorrected drift in the TOMS instrument (a similar drift is apparent in the SBUV-Dobson comparisons), limited sensitivity of the TOMS to increases in tropospheric ozone, and the effect of local increases in pollution levels on individual Dobson stations. ¿ American Geophysical Union 1988