Over a three-year period x-ray studies were made on a series of more than 1,500 women with breast lesions. It was found that the x-ray examination revealed a percentage of accuracy almost twice as great as that obtained by clinical examination. Occult carcinomas as small as 0.5 cm. in diameter can be detected by roentgenographic examination. The finding of these small unsuspected carcinomas, paradoxical as it might sound, offers the best prospect for cure. X-ray examination is mandatory in all cases presenting vague, unusual, or unaccountable breast symptoms.