Lymphocytic interstitial pneumonitis (LIP) is characterized by diffuse bilateral pulmonary infiltrations in both lower lobes. Pleomorphic lymphohistiocytes including mature lymphocytes, variable admixture of plasma cells and other mononuclear cells infiltrate within the pulmonary interstitium, ranging from widened septa to confluent masses. We report a case of LIP associated with Epstein-Barr virus in a patient with SLE and Sjögren's syndrome. A 50-year-old woman was admitted with insidious onset of progressive dyspnea for 20 days. She suffered from arthritis 10 years earlier without specific diagnosis. A radiography of chest has showed bilateral consolidative infiltrations with pleural effusion in both lower lung fields. Open lung biopsy documented lymphocytic interstitial pneumonitis which expressed Epstein-Barr virus genome in situ hybridization study. Following corticosteroid and cyclophosphamide therapy, clinical symptoms and radiologic infiltrations gradually remitted.