A neurological syndrome characterized by episodes of confusion, slurred speech, and unsteadiness is described in patients who have undergone jejunoileostomy for obesity. This syndrome has been noted in seven of 110 patients studied, although it may be more common. It appears to subside spontaneously or may respond to oral food restriction, with or without intravenous fluid plus vitamins and minerals. Episodes tend to recur in a given patient. Reversible changes in the EEG have been observed. Pertinent clinical and laboratory findings are described but no definite etiologic factor has been identified. The possible mechanisms involved in this syndrome of metabolic encephalopathy following jejunoileostomy are discussed.