Majority of the lung cancer occurs in developing countries. In case of Bangladesh it's a burden for health in both serest. A definitive diagnosis of lung cancer can help the surgeons and physicians for making decisions about the plan of treatment. The rapidity of diagnosis also alleviates the patient's anxiety whether the lesion is nonmalignant or malignant Several studies proposed the role of CYFRA 21-1 level in diagnosis of lung cancer and its better management. To find the sensitive, feasible and cost effective test for detection of lung cancer and to evaluate the CYFRA 21-1 with their histopathological findings. This case control study was carried out in the department of Medicine of National Institute of Diseases of the Chest and Hospital (NIDCH) Dhaka and Enam Medical College Hospital, Savar, Dhaka during the period from January 2017 to September 2017. We included a total of 80 subjects among them 40 diagnosed cases of lung cancer and 40 controls with diseases other than lung cancer. The mean normal (< 3.5) serum CYFRA 21-1 level was (Mean *SD) 1.10 t 1.5 with ranging from 0.87 ng /ml — 1.5 ng lint Normal level of CYFRA 21-1 was found in all 40 (100%) of controls. The mean of high (> 3.5) serum CYFRA 21-1 level was (Mean +-SD) 18.20 ± 13.63 with rangingfrom 6.9 ng hnl — 49.30 ng/ml. High level of CYFRA 21-1 level was found in maximum 35(87.5%) cases. High (> 3.5 rig/m1) serum CYFRA 21-1 level was found maximum in squamous cell carcinoma (20), next adenocarcinoma (15). Among 40 cases diagnosed as malignant by histopathology, serum CYFRA 21-1 level was compared with histopathological findings. The sensitivity of serum CYFRA 21-1 level in case of squamous cell carcinoma, adenocarcinoma and combined were 90.90%, 83.33% and 87.5% respectively. The sensitivity and accuracy of serum CYFRA 21-1 for squamous cell carcinoma was more than that of adenocarcinoma. So serum CYFRA 21-1 level was highly sensitive for squamous cell carcinoma.