This article describes an ultraviolet (UV) spectrophotometric method of determining hydrogen peroxide concentrations in solutions that contain potentially interfering organic compounds. The procedure is a modification of previously existing methods used to measure cobalt by hydrogen peroxide oxidation, which produces a green product with a strong absorption band in the UV region. The concentration of the product determined by absorption measurements can be correlated to the quantity of hydrogen peroxide originally present in the test sample after correction for UV absorption of the interfering organic compound. Includes 7 references, tables, figures.