On the basis of 170 double-contrast radiographic examinations of the small intestine, a description is given, in the first part of this paper, of the technique employed. Emphasis is laid, on the one hand, on duodenal intubation, which is easily effected with a Dotter-Bilbao tube and, on the other, on a study obtained by filling with a continuous barium column, the double-contrast being merely an adjunct. In the second part of the paper the results are analysed from a photographic and diagnostic standpoint: Photographically, duodenal intubation affords a clearer visualization of the jejunum but the chief merit of double-contrast radiography lies in the visualization of the ileum and the study it makes possible of the last ileal fold. With regard to diagnosis, from personal series, 20 % of organic lesions have been observed, although it must be admitted that this figure is certainly boosted by the selectivity of a specialized gastroenterologic unit. The interest of this technique rests also on the fact that the examination is very well tolerated by the patient and does not last more than two hours on an average.