Super-cooled liquid water droplets exist in clouds over the Antarctic Plateau in summertime at temperatures well below freezing. Knowledge of both the macro-physical and micro-physical properties of such clouds is important because general circulation and weather prediction models are very sensitive to cloud properties. A hydrometeor videosonde (HYVIS) was operated in January 2001 as part of the South Pole Atmospheric Radiation and Cloud Lidar Experiment (SPARCLE). The HYVIS was flown aboard a tethered balloon into low-lying clouds over South Pole within about 1 km of the surface. Some of the clouds sampled during the austral summer are composed entirely of super-cooled water droplets at temperatures around -30 C. The HYVIS images of cloud droplets are converted to digital images, which allows individual water droplets to be sized using image-analysis techniques. Preliminary estimates of the radii of the droplets typically range from a few micrometers to about 20 micrometers with a mode of about 7 micrometers. On a few, rare occasions, some large droplets are observed with radii around 40 to 50 micrometers.