Poly(3-acrylamidopropyl)trimethylammonium chloride (p(APTMACl)) hydrogels were synthesized and utilized as absorbents for the removal of toxic arsenate from aqueous medium. The pH-dependent swelling characteristics of the hydrogel were studied, and the experimental parameters that affect the absorption efficiency were investigated. Our results demonstrate that these types of hydrogels are highly effective in removing arsenate(V) anions from the aqueous environment. A removal efficiency of approximately 99.7% was obtained be immersing 1.5 g/l hydrogel in a solution containing 50 ppm As(V) at pH 9 for 360 min. Moreover, the hydrogels are very easy to handle upon absorption, avoiding issues related to the separation of traditional powder absorbents from water after absorption.