Chromium and antimony may coexist in industrial wastewater such as the textile and dyeing field. Sulfidated zero valent iron (S-ZVI) is attracting more attention due to its simple preparation and high reactivity with contaminants. The reaction with pollutants may be a complex mixture of redox, sorption, and coprecipitation. In this work S-ZVI was used to sequester Cr(VI) and Sb(III) simultaneously in open and well-mixed batch reactors. The correlation between Cr(VI) and Sb(III) sequestration by S-ZVI, the influence of different S/Fe molar ratios, the initial concentration of Cr(VI) and Sb(III), the initial pH and the addition of Fe(II) and other factors were investigated to evaluate the performance of S-ZVI and to demonstrate the reaction mechanism. Experimental results showed that S-ZVI could sequester Cr(VI) and Sb(III) efficiently and the S/Fe molar ratio had a dramatic effect on the removal rate, the highest kobs was obtained when the S/Fe molar ratio was 0.056. The X-ray photoelectron spectroscopy (XPS) showed that Cr(VI) could be reduced to Cr(III) and Sb(III) could be oxidized to Sb(V) simultaneously, adsorption and coprecipitation also coexisted in this system. A certain amount of Sb(III) could promote the sequestration of Cr(VI) but Sb(III) sequestration was hardly affected by Cr(VI). Furthermore, catalase was used as a masking agent of hydrogen peroxide, the results indicated that hydrogen peroxide may play an important role in the sequestration of Cr(VI) and Sb(III), which need to be further investigated.