The iodine content was determined in samples from nine different brands of cooking salt (NaCl), acquired at four-month intervals during the one-year period in Santa Maria, RS. Volumetric oxy-reduction analysis was performed using a 0.005 N sodium thiosulfate solution. The results have shown that iodine concentrations are often outside the normal range (9.6 to 17.0 mg I 2 / kg NaCl).