Cyberknife is a high precision, painless, non-invasive robot guided frameless steriotactic radiosurgery system. It is the first and only radiosurgery system designed for treatment anywhere in the body. Cyberknife uses continual X-ray image guidance technology and computer-controlled robotic mobility to automatically track, detect, and correct for patient movements and target without interrupting the treatment. Cyberknife has proven to be effective alternative to surgery or conventional radiation for treating many conditions like vascular abnormalities-AVM, head and neck tumors, nasal and orbital tumors, cervical tumors, trigeminal neuralgia, pituitary adenomas in sub-millimeter accuracy and provides enhanced ability to avoid critical structures. Cyberknife gives a renewed ray of hope for a better quality of life especially for patients with previously diagnosed inoperable or inaccessible tumors and for those who have already received the maximum amount of radiation through other treatment methods and offers quick recovery and return to normal life. Keywords: Cyberknife, stereotactic, robotic mobility, sub-millimeter accuracy