LAST year we demonstrated before the Radiological Society of North America the results of our studies in the practical utilization of pneumoperitoneum and its application to gynecology. Forestier at that time exhibited films illustrative of the use of an iodized oil in the diagnosis of uterine and tubal disorders. It occurred to us that, while the latter was a very valuable addition to our armamentarium, the combination of the two methods, pneumoperitoneum and transuterine iodized oil instillation, would undoubtedly be of more value than either alone. In the past year, we therefore made a number of observations utilizing this combined method. We desire now to demonstrate the results thus obtained and shall attempt to evaluate the combined method in terms of the other two separately. None of these methods has been used routinely by us in the diagnosis of our gynecologic material, but only in those cases in which the diagnosis was incomplete or unsatisfactory by other clinical means. The technic employed in this work is the same as described in our previous paper for the induction of pneumoperitoneum and the subsequent taking of films utilizing the Potter-Bucky diaphragm, the patient being in the partial knee-chest position following pneumoperitoneum. Before turning the patient over in this position, however, a bivalve vaginal speculum is introduced and a special cannula is inserted into the cervix, through which the iodized oil is instilled. To prevent the backflow of the contrast oil the cannula is fitted with a special olive-shaped rubber obturator through which the cannula passes. The olive is pressed firmly against the external os and traction is made with a single vulsellum on the anterior lip. This latter procedure can also be done after the patient has been placed in the knee-chest posture so that the iodized oil is instilled just before arranging the patient on the Bucky diaphragm. Only sufficient pressure is used during instillation to fill the uterine cavity and fallopian tubes. It is extremely difficult to gauge the amount of pressure needed, especially when using too small a syringe, or one with too small an opening, and for the purpose of obviating this difficulty we have employed a special glass syringe with an outlet large enough to permit of easy flow of the heavy oil (lipiodol). With the use of the roentgen-opaque oil only a limited amount of information is obtainable, such as the visualization of the uterine cavity and fallopian tubes, when filled. If there is a point of obstruction in the tubes, the iodized oil will pass only up to this point (Fig. 1). It is possible that one tube may be patent, this tube filling completely, the opaque media escaping from the fimbriated end, while the other tube will fail to show because of apparent occlusion.