This lecture defines the scope of Direct Ozone Injection into solid tumors, and introduces attendees to the ways in which Direct Ozone can be given under ULTRASOUND guidance (USG). Percutaneous USG guided Ozone injection is an exciting approach to destroying inoperable primary tumors or metastases in the liver in the treatment of hepatocellular (HCC), fewer than 40% of patients are candidates for surgery, and the rate of recurrence after curative surgery is high. Percutaneous techniques like Ozone Absolute alcohol & RFA are widely used for metastatic and small primary tumors. It serves as a bridge for transplant candidates, especially in relation to small primary lesions. Percutaneous Ozone is a minimally invasive, repeatable procedure with few complications. It is performed under Ultrasound guidance. Ozone results in a higher rate of complete necrosis and requires fewer treatment sessions than percutaneous ethanol injection (PEI). Long-term survival rates are also better. Our series of 4 patients compared well than the patients treated with Trans catheter arterial chemoembolization (TACE) Cholangiocarcinoma?s with obstructive biliary system responded well with direct USG Guided Ozone Injections.