During the last decade, radiation therapy has grown to become an important medical treatment in the treatment of cancer. The growth of this field has created a need for an electronic and mechanical support group to service the needs of the treatment centers (clinics). Because of the uniqueness of equipment, the maintenance criteria are somewhat different than that for other types of equipment. The information for this paper was derived from five years of experience that the Mallinckrodt Institute has accumulated through its own technical group plus information gained through discussions with other groups in the therapy field. The technical support group at Mallinckrodt Institute of Radiology (MIR) presently maintains six high-energy therapy machines, two simulators, and a superficial X-ray unit. Topics discussed include the technical personnel required, the duties of the group, working hours, suggested electronic/mechanical equipment, and other pertinent aspects.