Abstract: An intracavitary hyperthermic applicator comprising outer and inner coaxial conductors, electrical insulation between the conductors, the outer conductor terminating in a distal end spaced proximally from the distal end of the inner conductor, the outer conductor being slotted at a location spaced from the distal end of the outer conductor, defining a junction, outer and inner tubular sleeves of conductive material disposed coaxially over a length of the outer conductor, electrical insulation between the sleeves and between the inner sleeve and the outer conductor, conductive attachments securing the proximal ends of the sleeves to the outer conductor, and the outer sleeve terminating in a distal end spaced proximally from the distal end of the inner sleeve.