Pulmonary nodules and space occupying lesions are frequently detected on computed tomography (CT) scans of the chest or on chest radiographs. Many pulmonary lesions require a CT-guided transthoracic lung biopsy to obtain a cytological and/or histological diagnosis and guarantee sufficient and effective treatment, especially for patients with lung cancer. The author gives an overview on the different methods of obtaining biopsies and their risks and advantages. Furthermore the diagnostic safety and accuracy of the routine imprint cytology and cytologic and histologic work-up of tissue specimen are reviewed. The book is addressed to doctors who perform CT- guided transthoracic lung biopsies and want to know more about improving the diagnostic accuracy and safety of their procedures to guarantee the best treatment of their patients.