610 sacrorodiculographic and myelographic examinations were carried out injecting at lumbar level Iopamidol at 200, 300 and 370 mg I/ml concentrations. Immediate and early complications have been noticed in 18,52% of cases, i.e. sensation of pain during contrast injection, headache, nausea, vomit, neck stiffness, photophobia, epilepsy. In sacrorodiculographic examinations, side effects especially occurred by using 370 mg I/ml concentrations; in lumbar and thoracic myelographies, incidence of complications did not statistically differ by uing 300 or 370 mg I/ml concentrations. Side effects have occurred most frequently in cervical myelographies carried out with 370 mg I/ml concentration. Analysis of complications as well as radiographic results suggest to use Iopamidol at 300 mg I/ml concentration in sacrorodiculographics, in lower thoracic myelographies and in studies of narrowed, stenosed or obstructed canals; Iopamidol at 370 mg I/ml concentration may be used in upper thoracic studies and cervical myelographies.