(1) Background: Our work compossed 50 patients who were provisionally diagnosed to have mediastinal lesions. Full medical history, clinical examination and radiological investigations were performed. One or more of the following invasive diagnostic procedures were used to reach the histopathologic diagnosis: 1. Percutaneous CT guided biopsy which showed moderate positive results.(62%) 2. Video assisted thoracoscopic biopsy proved to be a sensitive method in well selected cases. (80%) 3. Open biopsy is the best diagnostic tool when all the other tools failed, and when complete resection of the lesions is anticipated. It showed 100% positively. (2) Aim of the work: To correlate findings of CT scan of the chest in mediastinal lesions with histopathology and to detect the sensitivity of both in diagnosis of mediastinal lesions.