The eruption of the Eyjafjallajokull volcano in April-May 2010 highlighted the ash-monitoring capabilities of a variety of sensors now in orbit and the benefits of making use of observations from multiple sensors. Dispersion of the volcanic ash across Europe and subsequent impacts on air traffic resulted in the adoption of safety guidelines on acceptable ash mass concentrations, placing new requirements on the plume transport models used to provide ash advisories. The CALIPSO satellite carries a two-wavelength polarization lidar and a three-band IR radiometer, operating since June 2006. Profiles of spectral and polarized lidar backscatter are used to identify volcanic ash. CALIPSO first detected ash on 15 April and observed the dispersion of the ash plume as it spread across Europe, providing unique observations complementary to passive satellite sensors and groundbased lidars. With a vertical resolution of 60 meters, CALIPSO provides detailed profiles of the vertical distribution of ash. With estimates of ash particle size, which can be obtained from IR observations, profiles of mass concentration can be derived. The observed plume heights and vertically resolved property retrievals can be used for testing the underlying physics of plume transport models and to refine eruption source parameters used in the models. In addition to the lidar, CALIPSO also carries a multiwavelength infrared imager, presenting possibilities for combined lidar-infrared detection and retrieval schemes. This presentation will illustrate capabilities of CALIPSO to identify and characterize the ash plume from Eyjafjallajokull.