Two patients with chronic mucocutaneous candidiasis and a defect in cellular immunity received a single injection of dialysable transfer factor from Candida-positive donors in an effort to reconstitute immunologic function. The transfer of cellular hypersensitivity was successful in one of the two patients and was monitored by skin tests and MIF production; however, the effect was temporary and did not change the clinical course of the patient's infection. The other patient did not respond eitherimmunologically or clinically to transfer factor at this time, although she did respond subsequently to repeated doses of transfer factor and amphotericin B therapy (Pabst and Swanson: Brit. med. J. 2:442, 1972). In another instance transfer factor from tuberculin-positive donors was used successfully to eradicate an infection in a patient with progressive primary tuberculosis and an acquired defect in cellular immunity. The patient had not responded clinically or bacteriologically after 7 1/2 months of antituberculous therapy, although the organism was shown to be sensitive in vitro to the drugs she was receiving. She received 6 doses of dialysable transfer factor over a 3-month period and during this time she responded clinically, bacteriologically and roentgenographically.