A series of lumbar myelographies -- 105 in 98 patients - was carried out with water-soluble Metrizamid (Amipaque R) in a concentration of 170 mg I/ml and showed side-effects in 32% and a quality of contrast similar to that of other water-soluble contrast media used before. The side effects were mild, of short duration and needed no treatment. There were no epileptic fits, tonic or clonic carried out 1 - 12 months later showed no signs of arachnoiditis. Dangers of more serious complications appeared to increase, the higher the level of injection into the spinal canal. A short survey of contrast media used in myelography and earlier experience of experimental or clinical side effects caused by Medtrizamid in myelography follows.