The first step in evaluating a patient with a possible diagnosis of caffeine intoxication is to obtain a careful history about all recent caffeine consumption. The possible use of beverages and medications – both prescription and over-the-counter (OTC) diet aids and energy pills – should be reviewed. Some beverages (e.g., caffeine-containing soft drinks) and medications (e.g., energy pills, aids to combat sleep, or diet pills) may not be recognized by the patient as containing caffeine. The amount of caffeine acutely consumed should help clarify the diagnosis of caffeine intoxica-tion, although it is important to determine whether the patient has been chronically consuming high doses of caffeine. If this is the case, the patient may be tolerant and therefore less likely to be experiencing caffeine intoxication. However, some clini-cians have reported that caffeine intoxication can occur even in the context of chronic caffeine use. The primary approach to the treatment of caffeine intoxication is to teach the patient about the effects of excessive caffeine consumption. In patients who are resistant to accepting the role of caffeine in their presenting symptoms, it may be useful to suggest a trial-off of caffeine as both a diagnostic and a potentially therapeutic probe.