Malignant lymphomas belong to the most important malignant diseases in western countries with an increasing incidence of Non-Hodgkin lymphoma. The thorax is the location of primary manifestation especially in patients with Hodgkin's disease. Progression of disease and therapy associated complications are frequently located in the chest. Based on morphological imaging criteria the two types of lymphoma cannot be differentiated, helpful for differentiation is, however, the way of disease spread. Primary and secondary thoracic lymphoma represent a diagnostic challenge in radiology: the patterns are variable in radiography as well as in computed tomography and alter under therapy. Radiological studies, especially CT, are an integral part of the staging process. MRI is considered advantageous for chest wall disease. PET as functional imaging technique has its proven role for staging of high grade lymphomas, the combination of functional and morphological information provided by PET-CT will become the first diagnostic standard in the future.