Lumbar metrizamide myelography (LMM) has been associated with a high incidence of side effects. A total of 94 patients underwent LMM for suspected disc disease or spinal stenosis. In Group 1 a 22-gauge spinal needle was used. Containing the same amount and concentration of metrizamide, an 18-gauge spinal needle was used in Group 2 after which there was partial withdrawal of the metrizamide (average withdrawal: 73%). In Group 1 a total of 38% of patients experienced one side effect whereas 8.5% had two side effects. In Group 2 a total of 8.5% of patients experienced one side effect and 4.25% had two side effects. This study demonstrates a statistically (P less than 0.003) lower incidence of side effects with metrizamide withdrawal after myelography.