The spatial growth of individual contrails of commercial aircrafts in the time range from 1 min to 60 min behind the aircraft is investigated by means of a ground-based scanning backscatter lidar. The growth in width varies between 18 m/min and 140 m/min, and the growth of the cross-section between 3500 m2/min and 25000 m2/min. These values cover the findings of model calculations and former investigations. The vertical growth is often limited by boundaries of the humid layer at flight level, but values up to 18 m/min were observed. In a single case a vertical growth of 4.5 m/s during the early vortex regime was derived from video images. ¿ American Geophysical Union 1995