Obesity is a serious health problem not only in the United States but also throughout the world. It is generally recognized that complications of the overweight state and obesity are responsible for thousands of deaths each year, because excess fat accumulation is associated with heart disease, stroke, and diabetes that significantly reduce life expectancy. Many have come to realize that most individuals, especially when elderly, require aids to prevent or overcome obesity and maintain a reasonable body fat mass. A restricted caloric diet and regular exercise remain the cornerstones of prevention and therapy; however, the average overweight individual cannot sustain the necessary therapeutic disciplines and needs safe, complementary means to supplement diet and exercise. Up to this point, drugs are not the answer due to safety concerns, leading many to seek safer, natural alternatives. Recently, oral intake of chitosan, a soluble fiber with reputed special properties, has become one possible solution to the problem. This review examines chitosan as an aid in the battle against fat accumulation.