The diagnosis and treatment of anemia in medical inpatients were studied. Anemia was detected from the admitting complete blood cell count, the medical charts were perused for management of anemia by the physicians, and the cases of anemia were classified by the investigators, using the complete blood cell count and peripheral blood smear. Anemia was seldom diagnosed in the traditional manner. In about 25 percent of cases, it was not even recognized. In about 20 percent, it was recognized but not evaluated or treated. In the 55 percent of cases adequately diagnosed and/or treated, the diagnosis was often more "situational" than analytic, the treatment more empiric than specific. Physicians ignored or misused information from the complete blood cell count and smear description and examined the smear themselves in fewer than one in 10 anemic patients. Not all of the missed cases of anemia were mild, expected from the patient's illness, or unimportant to the patient's care.