Anaplastic large cell lymphoma(ALCL) is a recently recognized large cell lymphoma characterized by large pleomorphic cells, with prominent nucleoli, expressing the CD3O(Ki-1) antigen. It is often misdiagnosed as metasfatic carcinoma, malignant histiocytosis or Hodgkin's disease. Primary pulmonary ALCL is extremely rare although it frequently involves extranodal sites, e.g. skin, bone, gastrointestinal tract, soft tissue and lung. We report a case of ALCL suspected as primarily involving lung.