Following the eruption of ‘Cumbre Vieja’ volcan ( Canarian islands) on 19 sept. 2021, the high-altitude ash plume spreaded over part of Europe. Filaments of the plume were clearly observed above Sesto Fiorentino (Florence) by means of INO CNR depolarization LIDAR (‘optical radar’) on days 24 and 25 september. On 24 sept the layer was at 2500-4000m altitude, while on 25 sept. was at 1500-3000 m. On 25 sept, an evident mixing of the volcanic layer with the local PBL, after midday, was observed. Even if we cannot exclude the concurrent presence of saharan dust, the calculated HYSPLIT back-trajectories showed an airmass origin close to Canarians. The high sensitivity achieved in the LIDAR-detection of ash/dust is obtained by measuring the depolarization of (initially linearly-polarized) light in the LIDAR elastic backscatter signal. The INO LIDAR, active from 2004, is intended for the continuous monitoring of dust and clouds (http://lidarmax.altervista.org/lidar/Lidaronline.php)