Despite the major technological advance in recent years, the goal-"Cure" or control of the most cancers havenot yet been achieved. These failures of cancer control are due either to local recurrence at the site of surgeryor to distant metastasis. In order to prevent regrowth of the cancer cells left at the time of surgery or toprevent spreading of cancer cells through the blood vessel or lymphatic channel at the time of surgicalmanipulation, preoperative irradiation has been practiced. Pre-operative irradiation means a planned combinedprocedure which requires that a predetermined dose of irradiation is followed after a stated interval by adefinite surgical procedure. Literatures about pre-operative irradiation have been reviewed on the theoreticalbasis and problems involved with practical procedures and advantages and disadvantages of the pre-operativeirradiation. There are two methods of pre-operative irradiation; Full dose method; to irradiate a dose of 4,000 to6,000 rads in 4 to 6 weeks and, Moderate dose method; to irradiate 2,000 to 3,000 rads in 2 tl3 weeks. The optimaltime interval between the completion of the irradiation and surgery is considered to be a period of 4 to 6 weeksin full dose irradiation and 1-3 weeks in moderate dose method. A review of experience with pre-operativeradiotherapy in cancer shows that full dose irradiation followed by radical surgical extirpation of the tumor andthe node-bearing areas has been used successfully in the management of neoplasms arising in many anatomical sites.Moderate dose of radiotherapy given in a short period of time followed by radical surgery has also been associatedwith imporved results in management of many tumor sites. The apparently favorable effects of moderate doseirradiation are of practical interest and include shorter duration of time under irradiation, the decreasedinterval before operation and the probable decrease in operative morbidity.