By far the most common indication for bronchoscopy is diagnostic. Within this category, the most common patient is someone with clinical or radiologic signs possibly caused by cancer. The bronchoscopist frequently has to answer the question of whether a suspicious lesion in the central airways or more peripheral parts of the lung is benign or malignant, primary lung cancer or metastatic spread from another malignancy. As such, this diagnostic procedure is initially especially intended for obtaining tissue for histologic investigation or material for cytology. Very often, the bronchoscopic procedure used in these patients is the simplest method for tissue procurement with little morbidity and almost neglectable mortality compared to other approaches for obtaining material from the suspicious lesion or assumed metastases. Besides being important in tissue procurement, it also has an important role as part of the procedure for the clinical staging of a lesion with proof of its malignancy, as well as in staging of lesions of unknown histology that are assumed to be malignant by other means. Examples of this are uptake of 18-fluoro-deoxy-glucose during PET or CT scan with a pattern of lobulation and spiculae, as is frequently seen in primary malignant tumors of the lung.