Intense stratospheric dust layers have been observed with a lidar at L'Aquila (42¿N, 13¿E) during the months of July and August 1982. These features were located at 22--26 Km with a maximum scattering ratio of 13. In one occasion a layer was also observed at 32 Km. Maximum integrated scattering is of the order of 0.001 sr-1. The almost daily frequency of the observations has revealed an unusually fast decrease of the altitude of the layers with an apparent velocity of 0.2--0.3 Km/day. This pattern is repeated in both the high altitude layers observed. It is speculated that this effect could be attrributed to the zonal distribution of the dust which in turn could depend on dust formation process.