Isotopes of radioactive iodine have a persistent lethal effect on the uncontrolled proliferation of tumor cells with a definite curative effect on tumors. It has been proved, up to 87.2% of 3-year's survival rate that could be achieved by radioactive seeds. Iodine-125 radioactive seeds have a long half life and low energy with excellent stable outcomes. Various effective isotopes with advanced techniques are used to place radioactive sources directly into a tumor, tumor bed in treating lung cancer. Lung brachytherapy is made-to-order to the clinical situation and can be in the form of permanent interstitial volume or planar implants as a radioactive sources that could be permanently imbedded into the tumor or tumor bed, or in the form of temporary interstitial, or endoluminal implants where radioactive sources irradiate a tumor bed over a certain length of time and then are removed. These treatments can be delivered over a short interval (high-dose rate [HDR]) or over a more protracted time (low-dose rate [LDR]). Also use of fastener staples to hold the radioactive seeds at target tissue for the optimum effect and stability. Other new techniques like HIFU (high intensity focused ultrasound) and advances in Immuno-Onco Therapies are emerging and may provide more advanced options for brachytherapy in near future. In this review article, significance of brachytherapy in lung cancer, implantation of Iodine-125 seeds, developed treatment system with low and high dose radiation, safety measures and advanced recent therapies are discussed.