Lidar measurements of Arctic (67.9¿N) cirrus clouds reveal a strong positive correlation between particle depolarization ratio and extinction-to-backscatter (lidar) ratio for ambient cloud temperatures above ~-45¿C, and an anti-correlation for colder temperatures. Similar correlations are evident in a 2-year midlatitude (53.5¿N) cirrus data set. These data suggest that robust relationships may exist between these particle optical properties that will facilitate the retrieval of cirrus extinction profiles from polarization-sensitive (spaceborne) elastic-backscatter lidars.