In an evaluation of the feasibility of using ferrous ion-activated persulfate oxidation to remediate methyl tert-butyl ether (MTBE)-contaminated groundwater, batch experiments were conducted to evaluate the effects of persulfate concentrations, ferrous ion concentrations, and coupled persulfate/hydrogen peroxide on the efficiency of MTBE degradation. Results showed that ferrous ion-activated persulfate oxidation was capable of degrading MTBE efficiently. Persulfate and ferrous ion concentrations correlated with MTBE degradation rates, although excess addition of ferrous ion decreased the MTBE degradation rates, likely because of competition between ferrous ion and MTBE for sulfate free radicals. Two main byproducts of MTBE degradation, tert-butyl formate and tert-butyl alcohol, were detected in the experiments; however, both subsequently degraded. Sulfate analysis results showed that appropriate addition of ferrous ion could prevent unnecessary persulfate decomposition.