Iron oxides (IO's) have been widely used for arsenic removal from water. Arsenic is a world-wide problem that has caused a range of diseases to the population that lives near polluted waters. Current technologies have scaled down the contamination level, but the problem remains, mainly in developing countries and rural areas. It is highly desirable to develop arsenic remediation technologies that are economically affordable and environmentally sustainable. This review discusses the importance of iron oxides for arsenic removal from water. The various iron oxide phases with different origins are discussed; e.g., hematites from both natural origins and theirs synthesis at the nanometer scale are discussed. The particular emphasis in arsenic adsorption on IO's is because iron oxide minerals are ubiquitously distributed in Earth's crust, and the synthesized counterparts can be prepared at low cost, even on small scales with non-sophisticated equipment. © 2012 Nova Science Publishers, Inc. All rights reserved.