Stereotactic Body Radiation Therapy (SBRT) is extracranial stereotactic radiosurgery or stereotactic radiation therapy, a newly emerging radiotherapy treatment method to deliver a high dose of radiation to the target, utilizing either a single dose or a small number of fractions with a high degree of precision within the body. The ability to deliver a single or a few fractions of high-dose ionizing radiation with a high targeting accuracy and rapid dose falloff gradients encompassing tumors with a patient provides the basis for the development of SBRT. A few fractions, the use of fiducial as a marker, image guidance and multiple radiation beam, and gating through a skin marker are unique technologies as compared to the conventional fractionated radiotherapy. The most common sites for these treatments are lung and liver, which are considered to parallel organs at risk. Recently, it was confirmed that prostate, spinal/paraspinal, head and neck, and pancreas tumors could be new candidates for these novel treatments. The preliminary reports show promising results with a relatively low complication rate. This article provides an overview of SBRT, the indication, descriptions of method including radiation dose and fraction size, the clinical data of lung and liver tumor, and discussions on potential areas of future investigations.