Contrast media induced nephropathy is a common cause of kidney failure in hospitalized patients. It has been suggested that high-osmolality contrast media caused less nephropathies than low-osmolality ones. The cost-effectiveness of High- (Iodixanol) and Low-osmolality (Iohexol, Iopamidol and others) contrast media are compared by means of a decision tree. The analysis showed that Iopamidol and Iodixanol strategies dominated all the others. The incremental cost-effectiveness ratio of Iodixanol compared to Iopamidol is $31.637.306 per adicional avoided nephropathy. Iodixanol strategy is cost-effective for a budget per patient higher than $980.000, or 50 ml vial cost lower than $57.000, or willingness to pay per nephropathy avoided higher than $32.000.000.