In talking of the relative merits of transvaginal roentgen therapy in carcinoma of the uterine cervix, I would like to insist first upon the fact that whatever the means of internal treatment and the technic of its administration, whether this is intracavitary or interstitial radium therapy or transvaginal roentgen therapy, it constitutes only a complement of the external irradiation. In the majority of cases treated, the results will depend mostly upon the adequacy of the external irradiation, which logically should have preceded the internal phase of the treatment. Allen, Caldwell, Pusey, and many among the pioneers of radiation therapy tried transvaginal roentgen therapy. Their sporadic attempts never crystallized. The late Edwin A. Merritt is to be credited for having revived this form of treatment and for eloquently and forcibly pointing out its possibilities in the treatment of carcinoma of the cervix. Merritt used the Ferguson bakelite specula after he had tried to use the walls of a urine specimen bottle as a speculum. Erskine devised an ingenious speculum made of expanding metal blades. This speculum is very applicable in early cases, but when the walls of the vagina are invaded, the use of an expanding speculum is not practicable. Wasson and other workers have preferred metal cylinders for the exclusive or even segmental irradiation of the cervix; this method may also be satisfactory in early cases, but I am convinced that it leads to serious inaccuracies. While collaborating with Merritt, I introduced a speculum composed of a metal head for the protection of the vulva and of a shaft transparent to radiations (Fig. 1). In its present form, this speculum allows a wide irradiation of the cervix, fornices, and adjacent parts of the parametria, while protecting, when required, the bladder and rectum (Fig. 2). In practice, a set of specula of several lengths and widths is necessary. In our hospital we have now treated with transvaginal roentgen therapy following external irradiation, over 200 consecutive cases of carcinoma of the cervix of all stages. Not a patient has been refused treatment, none has received radium, and very few have not completed treatment. Of 52 primary cases that applied for treatment in our hospital in 1943, only 2 failed to receive complete treatment. The patient is placed in the lithotomy position with the legs comfortably supported. The table is tilted to allow the intestine to fall out of the pelvis. The widest and longest speculum which can be introduced is used. The speculum head is adaptable to a corresponding part in the tube-head (Fig 3.) We prefer radiations of moderate penetration, such as obtained from 140 to 150 kv. equipment, but also prefer to filter as heavily as possible, usually through 0.5 mm. of copper. The target-cervix distance is 25 cm. It is preferable to administer the treatment within two weeks, before the appearance of vaginal radio-epithelitis.