Protein-calorie malnutrition, or both, affects the morbidity and mortality of patients undergoing operations. Laboratory assessments of nutritional status consisting of evaluations of serum albumin levels and total lymphocyte counts are valid tests of a patient's nutritional status. In this study we examined the influence of preoperative nutritional status on morbidity in twenty-three diabetic patients who underwent a Syme amputation. All of the patients met Wagner's criteria for a Syme-level amputation, but in only 43 per cent (ten patients) did the amputation heal at this level, which was chosen by Wagner's criteria alone. Of the seven patients who, in addition to meeting Wagner's criteria, had a serum albumin level of at least 3.5 grams per deciliter and a total lymphocyte count of at least 1500 cubic millimeters, in six (86 per cent) the amputation healed at the Syme level. In contrast, the Syme-level amputation healed in only two of the eleven patients who met the criteria of Wagner but who had a serum albumin level of less than 3.5 grams per deciliter and a total lymphocyte count of less than 1500 cubic millimeters.