World Health Organization statistics identify 150 million people with diabetes mellitus worldwide and suggest that this figure may double by 2025. In countries with a western lifestyle, the number of patients admitted for renal replacement therapy with diabetes as a co-morbid condition has increased significantly up to three to four times in a period of 10 years. Diabetes and renal failure are thus tightly linked diseases, and so is anemia. However, whether anemia may be worsened and/or directly, at least in part, caused by diabetes is not clearly elucidated yet. In this article, we review the prevalence, pathophysiology and consequences of anemia in diabetic patients.