Surgery remains the first option for curing early stage lung cancer. However, many patients are diagnosed at an advanced stage, and thus miss the chance to undergo surgery. As such patients derive limited benefits from chemotherapy or radiotherapy, alternatives based on local control have emerged, including iodine-125 seed implantation. The Interstitial Brachytherapy Society, Committee of Minimally Invasive Therapy in Oncology, the Chinese Anti-Cancer Association organized a group of multidisciplinary experts to revise the guidelines for this treatment modality. It aims to standardize iodine-125 seed implantation procedures, inclusion criteria, and outcome assessment to prevent and manage procedure-related complications.