Simultaneous profiles of aerosol backscatter ratio were measured over Lauder, New Zealand (45 ¿S, 170¿ E) on the night of November 24, 1992. Instrumentation comprised two complementary lidar systems and a backscattersonde, to give measurements at wavelengths 351, 490, 532, and 940 nm. The data from the lidars and the backscattersonde were self-consistent, enabling the wavelength dependence of aerosol backscatter to be determined as a function of altitude. This wavelength-dependence is a useful parameter in radiative transfer calculations. In the stratosphere, the average wavelength exponent between 351 and 940 nm was -1.23¿0.1, which was in good agreement with values derived from measured physical properties of aerosols. ¿American Geophysical Union 1994