Aerosol extinction-to-backscatter ratio profiles from surface level to 25 km at 690 nm wavelength are derived from simultaneous nephelometersonde and backscattersonde measurements. The stratospheric values are altitude dependent and range from about 35 to 70 sr. These values are in satisfactory agreement with previously reported estimates employing other techniques and are consistent with optical calculations utilizing aerosol size distributions characteristic of the volcanically disturbed period during which the measurements were made (summer and fall 1992). ¿ 1997 American Geophysical Union