Background and Objective: Lung cancer is the leading cancer killer and is the second most frequently diagnosed cancer behind prostate in men and breast cancer in women. Staging has a very important role in determination of disease extension and therefore in deciding about the kind of treatment. The aim of this study is showing the effect of surgical method in lung cancer staging and its impact on selection of treatment in patients with lung cancer. Materials and Methods: In this study (case series) 100 in-patients diagnosed to be suffering from lung cancer in the thorax ward of Tabriz Imam Khomeini Hospital were studied in the course of two years. In the first place, a highly precise history was taken from every in-patient diagnosed to be suffering from lung cancer in the thorax ward. They were, then, examined thoroughly and all of the symptoms and signs were recorded. Paraclinical studies were started with chest x ray. Mediastinoscopy, Mediastinotomy, Thoracoscopy, Thoracotomy, cervical lymph node biopsy or pleural fluid tap for precise staging were performed if indicated. After recording all the results in a questionnaire, we started the processes of staging of the disease. After that, the most appropriate decisions with regard to the treatment of the disease were made. Results: In this study 67 people (67%) were male and 33 people (33%) were female. Stages of lung cancer were done by surgical and non surgical methods in the patients studied. Different stages of the disease were found to be SIA 3%, SIB 25%, SIIA 1%, SIIB 7%, SIIIA 15%, SIIIB 23%, and SIV 26%. Conclusion: In this study, the use of surgical methods played a major role in exact staging of lung cancer and treatment protocol was changed in 29% of patients and also showed that, the use of surgical method improves the accuracy of the staging and therefore can extremely affect the kind of treatment in the patients with lung cancer. References 1- Shields Tw, LoCicero J, Reed CE, Feins RH. Genral thoracic surgery. Seventh edition. Philadelphia, USA: Lippincott William and Wilkins 2009. 2- Alexander Patterson G, Griffith Pearson F, Cooper JD, et al. Pearson's thoracic surgery and esophageal surgery. Thirth edition. Philadelphia: Churchill Livingstone 2008. 3- Naidoo R, Windsor MN, Goldstraw P. Surgery in 2013 and beyond. J Thorac Dis. 2013 5: 593-606. 4- Brunicardi FC, Andersen Dk, Billiar TR, et al. Schwartz's principles of surgery. Ninth edition. United States of America: McGraw-Hill companies 2010. 5- Passlick B. Initial surgical staging of lung cancer. Lung cancer. 2003 42: 21-5. 6- Howington JA, Blum MG, Chang AC, et al. Treatment of stage I and II non-small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American college of chest physicians evidence-based clinical practice guidelines. Chest. 2013 143: 278-313. 7- Taghipour Zahir S, Mirtalebi M. Survival of patients with lung cancer, Yazd, Iran. Asian Pacific J Cancer Prev. 2012 13: 4387-91. 8- Noronha V, Dikshit R, Raut N, et al. Epidemiology of lung cancer in India: focus on the differences between non-smokers and smokers: a single-centre experience. Indian J Cancer. 2012 49: 74-81. 9- Alamoudi OS. Lung cancer at a university hospital in Saudi Arabia: a four-year prospective study of clinical, pathological, radiological, bronchoscopic, and biochemical parameters. Ann Thorac Med. 2010 5: 30-6. 10- Rawat J, Sindhwani G, Gaur D, et al. Clinico-pathological profile of lung cancer in Uttarakhand. Lung India. 2009 26: 74-6. 11- Santos-Martinez MJ, Curull V, Blanco ML, et al. Lung cancer at a university hospital: epidemiological and histological characteristics of a recent and a historical series. Arch Bronconeumol. 2005 41: 307-12. 12- Sahin F, Yildiz P. Radiological, bronchoscopic and histopathologic characteristics of patients with primary lung cancer in Turkey (2006-2009). Asian Pac J Cancer Prev. 2011 12: 1947-52. 13- Hashemzadeh S, Hashemzadeh K. Epidemiological study of lung cancer in East Azerbaijan, Iran. J Cardivasc Thorac Res. 2009 1: 7-12. 14- Bhurgri Y, Bhurgri A, Usman A, et al. Patho-epidemiology of lung cancer in Karachi (1995-2002). Asian Pac J Cancer Prev. 2006 7: 60-4. 15- Eggeling S, Martin T, Bottger J, et al. Invasive staging of non-small cell lung cancer-a prospective study. Eur J Cardiothorac Surg. 2002 22: 679-84. 16- Wang X, Zheng L, Ling L, et al. Prospective comparison of CT versus mediastinoscopy in preoperative evaluation of mediastinal lymph node status in patients with non-small cell lung cancer. Zhonghua Zhong Liu Za Zhi. 2009 31: 42-4. 17- Wang X, Zheng L, Zhang SY, et al. Risk factor analysis of mediastinal lymph node metastasis in non-small cell lung cancer patients and the strategy of mediastinoscopy prior to surgery. Zhonghua Zhong Liu Za Zhi. 2009 31: 456-9.