We1 have recently suggested that alpha-dinitrophenol (1-2-4) might have therapeutic value in conditions in which an increased metabolic rate would be beneficial. Study of its pharmacologic properties shows that it has the power to increase metabolism to very high levels without causing important damage to vital organs and functions. Serious harm is apparently only caused by the drug in large doses which produce too great metabolic stimulation, with resulting fever. In low, or therapeutic, doses, the metabolism may be increased 50 per cent or more over considerable periods of time without unpleasant symptoms or toxicity. Such an action is useful in treating obesity, since the increased metabolism results in loss of weight, just as it does with thyroid medication. This paper is in the nature of a progress report on results obtained to date of treating 113 consecutive cases of obesity observed in clinic and private practice.