Arsenic (As) is a highly toxic metalloid that occurs naturally in the environment, however, anthropogenic activities have also caused this element occurrence in water and soil. The objective of this study was to evaluate phytoremediation capacity of Eleocharis macrostachya to remove As from the mining soils using cryptomelane (KMn8O16) as a chemical stabilizer. Experiment was established under greenhouse conditions during 70 days (10 weeks) using 20 pots with capacity of 3 kg of soils. 15 pots were applied 5 g of cryptomelane, while five pots were considered as a blank. The variables determined were soluble and total As in soil and plant (root and stem). 89% of the As was retained in the root and the rest in stem. The arsenic concentration, both in root and stem, was higher in the control soil than that with cryptomelane addition, which confirms that the chemical stabilizer retains or maintains less bioavailable arsenical compounds.