Nitric oxide and ozoen concentrations in the lower stratosphere have been measured from a high-altitude research aircraft using in situ measuring techniques. Results of several geographical surveys are presented along with predictions of two two-dimensional stratospheric models. Meridional and zonal data were obtained in June 1974 and in June, July, and August 1975. At longitudes 122¿-158¿W the meridional data taken between 5¿ and 80¿N latitude show an increasing NO concentration with latitude, by a factor of 4 at 21-km altitude and a less marked increase at 18 km. The minimum NO concentation at 21 km is observed at 5¿N latitude and is about 6¿108 cm-3. Zonal data at latitudes 22¿--38¿ taken from 55¿ to 176¿N longitude show little variation of the NO and O3 concentrations with longitude.