The long, occult phase of pre-invasive carcinoma of the uterine cervix provides the clinician with his greatest opportunity in the actual prophylaxis of invasive cancer. By the use of four-quadrant biopsies and Papanicolaou smears, the authors increased by almost 20 times the frequency of diagnosis of preinvasive carcinoma of the uterine cervix. Radiation therapy of invasive carcinoma in 147 patients produced five-year "cure" in 84 per cent of stage I cases, 65 per cent of stage II cases. The over-all rate for stages I to IV, inclusive, was 51 per cent. Surgical management of this form of cancer, with preservation of the urinary tract, is an inadequate operation as judged by the extirpative standards observed in operations for cancer at other major anatomical sites. Improvements in technique of irradiation, more accurate measurements of depth dosage at critical sites, and more uniform dosage throughout the parametrial areas, have decreased the incidence of major complications of irradiation. Radical panhysterectomy and pelvic node dissection should be reserved for patients proved to have radioresistant lesions.The application of routine block dissection of pelvic nodes for Stage I and Stage II lesions, clinically controlled by irradiation, is of doubtful theoretic, and no evident practical value. Subject to future evaluation, pelvic eviscerative procedures seem to offer some salvage in cases of recurrent (occasionally primary) advanced lesions in rigidly selected patients.