Abstract : Objective: This study aims to evaluate the value of using mediastinoscopy in the diagnosis and treating of mediastinal lesions in lung cancer.Lung cancer is known to be the leading cause of cancer mortality globally, and it is also ranked first on the prevalence of cancer against the planet’s population. Materials and methods: the study was performed by mediastinoscopy on 106 patients to diagnose lung cancer. We have used general clinical, laboratory, endoscopic (EBUS-TBNA, CMM), radiographical (CT, PET-CT), morphological, immunohistochemical, and statistical methods of study. For applied mathematics analysis results, we used Statistica for Windows Version 10.0 (Stat Soft INC., USA). Parameters are given within the form M±m, where M is the mean, m is the standard deviation. In the case of p<0.05, variations were set as statistically vital. Results: The number of patients in the study (who performed mediastinoscopy 106, 65 were represented by lung cancer). Conclusion: Mediastinoscopy remains the most effective diagnostic investigation of choice for paratracheal and retrovascularmediastinal pathology, especially in lung cancer.