The diagnosis of pure iron-deficient anemia or anemia of chronic disease is easy. However, in mixed situations, conventional laboratory tests for iron status are influenced by the inflammatory response and their diagnostic accuracy may be undermined. New tests are available but grey zones and diagnostic uncertainties sometimes remain. The objective of this article is to give an overview of the current diagnostic tools for the evaluation of the iron metabolism and to provide a practical diagnostic algorithm for the evaluation of iron-deficient anemia.