A 72-year-old woman with a dry cough and dyspnea on exertion was admitted to our hospital. A chest radiograph showed reticular opacities and volume loss in both lower lung fields. She was troubled with xerostomia and her laboratory test showed positive reaction for anti SS-A and SS-B antibody. Labial biopsy led to a diagnosis of primary Sjogren's syndrome (pSjS). Lung biopsy specimens obtained by video-assisted thoracoscopic surgery (VATS) revealed interstitial pneumonia. On the sixth postoperative day, hypoxemia acutely worsened and her chest radiograph showed widespread diffuse ground-glass attenuation. A diagnosis of acute exacerbation was made, and steroid and immunosuppressive therapy was started. In spite of intensive therapy, she died due to respiratory failure. We report a rare case of interstitial pneumonia with pSjS resulting in acute exacerbation.