Nitric oxide was measured, by chemisluminescence, over the altitude range 14-40 km during three balloon flights from Palestine, Texas, in fall of 1977 and 1978. The three height profiles were quite similar, as were the height profiles of ozone and temperature. Our three profiles agree reasonably well with those generated by one-dimensional models at the upper end of the altitude range of the measurements but are higher than the model profiles at the lower end of the altitude range. The integrated column densities from our measurements agree with those measured directly by long-path infrared. The profiles obtained in these and other recent flights are higher than those we reported before using earlier versions of the instruments. Possible sampling errors in the earlier instruments are discussed. Caution is advised in attributing stratospheric variability to differences in NO profiles obtained by isolated measurements. The need for simultaneous measurements using more than one technique is stressed.