The paper presents the results of the accuracy assessment of UAV/UAS imagery and digital processing for inventory mapping. The test object was an industrial estate in the Stryków municipality. The photo block (581 photos, GSD was 4.6 cm) registration was performed using Trimble®UX5 UAS equipped with Sony NEX-5T 16 MP digital system camera. The automatic aerial triangulation with self-calibration using the bundle block adjustment was performed and dense point clouds, digital surface model (DSM) and finally an orthomosaic were generated in Agisoft Photoscan and in Pix4Dmapper Pro software. The results of photogrammetric 3D data collection with an existing base map, which was elaborated using direct geodetic detailed surveys, were compared in AutoCAD Civil 3D 2017 suite. The generated DSM's were additionally analyzed using CloudCompare application. The obtained accuracy of photogrammetric 2D vectorization fulfils the accuracy requirements of the 1 st survey group of terrain details, specified in Polish geodetic technical norm.