The use of 3-D visualisation can provide a significantly improved understanding of the content of NDT data sets. This paper describes an advanced, PC-based Workbench for the reconstruction, visualisation and analysis of 3-D ultrasonic NDT data in an interactive CAD environment. The software combines analysis features of established 2-D packages with facilities for real-time data rotation, interactive orthogonal/oblique slicing and ‘true’ image réconstruction. A speciality of the Workbench is the tight integration between CAD (imported from commercial packages or generated internally), image formation and defect analysis. Inspection data, ultimately from a variety of methods, is reconstructed as a 3-D image and visualised with the CAD model. During main-beam reconstruction, scanning surface shape and reflection from component boundaries is accounted for through interaction with the full 3-D model of the component. Subsequently, sub-volumes within the image may be reconstructed to include mode conversion at the surfaces: to produce a ‘true’ image. Thus indications are correctly positioned, even if multiple reflections or mode conversions are involved. Sub-sets of images can be formed, comprising data pertaining to just one particular bounce. The CAD model can be adjusted to take account of variations in component geometry, with subsequent data reconstruction in the modified specification.