Cystic lesion, malignancy and interstitial pneumonia are well-known as pulmonary complications of patients with von Recklinghausen's disease. We report herein an unusual patient with distal acinar emphysema and interstitial pneumonia of prominent hypercellularity demonstrated by transbronchial biopsy and broncho-alveolar lavage fluid (BALF). Six months after quitting smoking, the total cell count of BALF was remarkably reduced. This patient remains stable under 5-year observation in terms of symptoms and findings of both BALF and pulmonary function tests. Quitting smoking may have facilitated a favorable prognosis for the particular lung disease complicated in this patient.