A type of cancer that begins in the lungs is referred to as lung cancer. It is the leading cause of cancer deaths in the world. Smoking increases the risk of lung cancer significantly. Some of the symptoms of lung cancer are persistent cough, blood streaked sputum, shortness of breath, chest pain, hoarseness, weight loss, bone pain and headache. The tests which can be used to diagnose lung cancer are imaging tests, sputum cytology, tissue sample, needle biopsy, mediastinoscopy and bronchoscopy. The treatment for lung cancer includes chemotherapy, radiation therapy, stereotactic body radiotherapy, targeted drug therapy, immunotherapy, palliative care, and surgeries such as wedge resection, segmental resection, lobectomy, and pneumonectomy. This book elucidates the diagnosis and treatment in relation to lung cancer. Different approaches, evaluations, methodologies, and advanced studies on this disease have been included herein. This book will serve as a reference to a broad spectrum of readers.