Ground based measurements of stratospheric nitrogen dioxide during morning and evening twilight have been made at Lauder, New Zealand, 169°40′E longitude and 45°04′S latitude during January and February 1979. The analysis shows that ozone absorption overlying the nitrogen dioxide absorption bands cannot be ignored. After correcting for ozone absorption the mean vertical column abundance of nitrogen dioxide was found to be 2.9 × 1015 cm−2 (evening, solar zenith angle = 90°) and 1.1 × 1015 cm−2 (morning, solar zenith angle = 90°).