The majority of newly diagnosed lung cancers are nonresectable and usually treated with chemotherapy, radiotherapy, or both. Malignant and recurrent endobronchial lesions are responsible for the majority of mortality from postobstructive pneumonia, respiratory failure, and sepsis in patients with lung cancer. Endobronchial brachytherapy (EBB) is a form of localized palliative radiation therapy that aims to control the growth of tumors and achieve reductions in their sizes. Significant improvement in clinical symptoms such as dyspnea, cough, hemoptysis, lung reaeration, and postobstructive pneumonia has been achieved with this treatment modality. EBB has been used to treat lung malignancy in the following clinical situations: (a) symptomatic endobronchial lesions, (b) early-stage malignancy in patients who are not surgical candidates, (c) locally advanced disease with involvement of the nearby anatomic organs (bones or major vessels) and inability to achieve free margins, (d) carcinoma in situ, and (e) mesothelioma. There are three types of radiotherapy: low-dose rate (LDR), high-dose rate (HDL), and pulse dose rate (PDR). HDR has significantly shortened the treatment time, minimized the need for hospitalization and associated costs, and decreased catheter dislodgment. It is becoming the most frequently used brachytherapy treatment option.