The stratospheric NO2 mixing ratio profile in the 20-40 km altitude range is derived from balloon-borne observations of the solar spectrum in the visible region. By comparisons of high sun and low sun spectra at float altitude (~40 km), a number of NO2 features are identified. The resulting NO2 profile shows a gradual increase above 20 km to a peak value of 13 ppb(v) near 35 km, followed by a gradual decrease to 10.5 ppb(v) at 40 km.