A method for modelling and visualizing human lungs using knowledge of lung anatomy and high resolution CT (HRCT) images is presented. The model consists of a symbolic description of lung anatomy and a 3D atlas. The 3D atlas is constructed using HRCT volume data. A few anatomical landmarks are determined and are used to divide the lungs into anatomically and diagnostically important regions. The landmarks and the lung regions enable accurate mapping of the model to patient data and enable the system to deal with image and human variability. The model can be displayed as a set of labelled axial slices and as a 3D model of the lungs. The 3D visualization enables rotation and viewing of lung structures, lung features and lung regions from different angles.