As an adjunct to routine pantopaque myelographic studies in 8 patients, cinemyelographic studies were made of the contrast medium movement on prompt jugular compression (Queckenstedt test). Isometric lumbar cerebrospinal fluid manometric studies were simultaneously performed, using a new strain gauge minitransducer, linked with a direct writing recorder. It was found that jugular compression displaced the contrast material 3 to 5 vertebral bodies caudally within 0.5 seconds. Maximum contrast medium flow velocity in the cervical and thoracic area varied between 9 and 43 cm. per second. In the lower lumbar canal there was no caudal shift, but a marked distention of the sac, with an approximately 40 per cent increase in lateral diameter. The jugular compression also brought about improved visualization of the root sleeves by contrast medium filling. The findings confirm assumptions made on the basis of isometric manometrics, that the Queckenstedt maneuver normally induces a rapid and marked downward bulk shift of spinal fluid. Previous opinions on the dynamics and adequacy of open-end manometric studies are refuted by the present observations. The diagnostic value of performing the Queckenstedt test at the time of myelography is emphasized, both for the evaluation of existing obstructions and the visualization of lumbar root sleeves.