A 46-year-male smoker presented with cough and fever to a chest physician, who on the basis of chest X-ray started him on antitubercular treatment. However, further evaluation suggested that the patient was suffering from a rare disease, i.e. Anaplastic large cell lymphoma of lung. Although lung involvement in cases of lymphoma is observed in as high as 40% of cases, in autopsy series, the exact clinical incidence is not known. One of the largest lymphoma groups reported it to be around 25%. However, primary pulmonary lymphomas have been extremely rare (0.4%), and whenever present they are of (Mucosa Associate Lymphoid tissue) MALT type, with occasional diffuse large cell lymphomas. The anaplastic variant is extremely uncommon. Usually the treatment results are satisfactory with more than 80% of the cases surviving even after 3 years. Here we report the case of anaplastic primary nonHodgkin's lymphoma of lung and review the literature.