Adult onset still's disease usually presents with high grade intermittent fever, polyarthritis, salmon pink evanescent rash and hepatosplenomegaly. Pulmonary involvement in the form of pneumonitis, as a presenting feature is very rare. We report a case of a young lady who presented with fever, cough and respiratory distress. Chest X-ray revealed patchy infiltration in left upper lung zone. She was subsequently diagnosed as Adult onset Still's disease. There was no improvement in clinical condition despite five days of antibiotics. On trans-bronchial lung biopsy (TBLB) proved she had interstitial pneumonitis and responded dramatically to steroid treatment.