Adult Still's disease is characterized by a high spiking fever, transient skin rash, and polyarthralgia. Joint pain is one of the major complaints and is often intractable. We assessed the efficacy of granulocyte and monocyte adsorption apheresis (GCAP) therapy for treating arthralgia in adult Still's disease. A 33-year-old woman with adult Still's disease who suffered from recalcitrant arthralgia resistant to systemic corticosteroids was treated with GCAP therapy. She underwent five GCAP treatments at 5-day intervals. Her joint pain responded dramatically to the GCAP therapy, suggesting that GCAP may be useful for treating adult Still's disease. We present a detailed description of the patient and this novel therapy.