Interstitial implantation is invaluable in the management of patients with extensive or large volume gynecologic malignancies, significant anatomical distortion, or recurrent disease. Such techniques are necessary components of the brachytherapy services available to patients with gynecologic malignancies giving superior results in terms of local tumor control and survival compared to those achieved with external beam alone or inadequate intracavitary applications. Local tumor control with an acceptable risk of complications can be achieved for these challenging disease presentations if these techniques are implemented skillfully through the joint efforts of the radiation oncologist and gynecologic surgeon.