Chronic overdosage with salicylates can produce a syndrome of chronic salicylate intoxication. The main features of this syndrome are confused, sometimes bizarre, behavior and hyperventilation. The measurement of serum salicylate and carbon dioxide provides reliable laboratory confirmation of the diagnosis and may prevent mistaking the condition for frank hysteria, diabetic coma, or other causes of organic delirium. Five patients are reported who suffered from various primary diseases but were hospitalized for complaints directly related to salicylate poisoning. In one patient, papilledema appeared to be the result of the salicylate intoxication.