The scope of this study was to evaluate an innovative adsorbent, nanocrystalline hybrid surfactant-akaganeite (denoted as Akh), for arsenate ions removal from dilute solution. Akh was synthesized in the laboratory using FeCl3 as the precursor and a cationic surfactant, hexadecyl-trimethylammonium bromide, as modifier. Ak(h) presented a significantly higher arsenate adsorption capacity (about 180 mg As(V)/g) than the pure nanocrystalline akaganeite (denoted as Ak, about 120 mg As(V)/g). The kinetics of adsorption obeyed a pseudo-second-order rate equation. Higher ionic strength results in higher arsenate adsorption. The new adsorbent was investigated with X-ray powder diffraction, N-2 adsorption-desorption (BET), Fourier transform infrared spectra, and X-ray photoelectron spectroscopy methods for better understanding the effects of surface properties on arsenate adsorption.