A highly efficient adsorbent for arsenic removal from water has been prepared by impregnating high surface area iron oxides on glass fibers. Arsenic in water can easily and efficiently be removed by this adsorbent, without the need to pre-oxidize As(III) to As(V). The iron oxides coated on glass fibers (IOCGFs) can remove both arsenic species well below EPA MCL (10ppb). IOCGFs should have the following four additional advantages: greatly improved contact efficiency; higher adsorption capacity because of high surface area; low cost and easily available adsorbent since the starting reagents (FeCl3 and NH3 center dot H2O) and glass fiber are cheap and readily available; and high adsorption efficiency of As(III) and As(V).