Acute Generalized Exanthematous Pustulosis (AGEP) is a acute febrile eruption characterized by nonfollicular sterile pustules on an edematous erythematous base. In over 90% of cases, AGEP is caused by a drug, most commonly antibiotics and anticonvulsants. Bupropion/naltrexone is a combination drug used for weight loss and has been reported as a rare cause of AGEP. A 38-year-old woman with a past medical history for atopic dermatitis presented with erythematous eruption with millimeter-sized pustules on the whole body. She had recently received oral bupropion/naltrexone to lose weight for 3 weeks. Laboratory tests showed an elevated white blood cell count with neutrophilia and elevated liver enzymes. Cultures of pustules were negative. A skin biopsy taken from the thigh revealed subcorneal pustule associated with neutophilic spongiosis and a papillary infiltrate. Based on the clinicopathological correlation, we speculated the acute generalized exanthematous pustulosis due to bupropion/ naltrexone. Intravenous dexamethasone therapy was initiated and bupropion/naltrexone was discontinued. While improving, desquamation was remarkable. After 2 weeks, she was discharged in good condition with oral methylprednisolone treatment. After 4 weeks, symptoms resolved, laboratory tests were normal, and oral methylprednisolone was discontinued. Herein, we report the rare case of bupropion/ naltrexoneinduced acute generalized exanthematous pustulosis.