Vertical profiles of the rate of linear change (trend) in the altitude range 15–50 km are determined from decadal O<sub>3</sub> time series obtained from SCIAMACHY<sup>1</sup>/ENVISAT<sup>2</sup> measurements in limb-viewing geometry. The trends are calculated by using a multivariate linear regression. Seasonal variations, the quasi-biennial oscillation, signatures of the solar cycle and the El Niño–Southern Oscillation are accounted for in the regression. The time range of trend calculation is August 2002–April 2012. A focus for analysis are the zonal bands of 20° N–20° S (tropics), 60–50° N, and 50–60° S (midlatitudes). In the tropics, positive trends of up to 5% per decade between 20 and 30 km and negative trends of up to 10% per decade between 30 and 38 km are identified. Positive O<sub>3</sub> trends of around 5% per decade are found in the upper stratosphere in the tropics and at midlatitudes. Comparisons between SCIAMACHY and EOS MLS<sup>3</sup> show reasonable agreement both in the tropics and at midlatitudes for most altitudes. In the tropics, measurements from OSIRIS<sup>4</sup>/Odin and SHADOZ<sup>5</sup> are also analysed. These yield rates of linear change of O<sub>3</sub> similar to those from SCIAMACHY. However, the trends from SCIAMACHY near 34 km in the tropics are larger than MLS and OSIRIS by a factor of around two. <br><br> <br><br> <sup>1</sup> SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY <sup>2</sup> European environmental research satellite <sup>3</sup> Earth Observing System (EOS) Microwave Limb Sounder (MLS) <sup>4</sup> Optical Spectrograph and InfraRed Imager System <sup>5</sup> Southern Hemisphere ADditional OZonesondes