Adult onset Still's disease(AOSD) is characterized by a high spiking fever, a transient rash, and arthritis. The clinical features include lymphadenopathy, hepatospleno-megaly, serositis, and sore throat. Leukocytosis is generally marked, but rheumatoid factor and ANA tests are negative. Respiratory system involvement is more common in AOSD than it is in childhood. The most common symptom is pleuritic chest pain with or without effusions. Rare cases of interstitial pneumonitis accompanied by AOSD have been reported. We report a case of AOSD with interstitial pneumonitis, which developed in two consecutive years and was successfully controlled with coriticosteroid therapy.