A 46-year-old man was admitted because of an increasingly severe cough and dyspnea on exertion. For 13 years, he had inhaled sand containing 100% crystalline silica (SiO2). Chest radiographs revealed right pneumothorax and diffuse small nodular and ground-glass opacities in both lungs (especially in the upper lung fields). A chest CT scan disclosed several bullae in both upper lobes, and an open lung biopsy was performed along with resection of these bullae. Subsequently, silicotic nodules containing silica and PAS-positive materials were recognized in the alveolar spaces in the histological findings, and a diagnosis of silicoproteinosis was made. We have reported on this case of silicoproteinosis with pneumothorax which progressed for over one year and which showed unusual radiological findings dissimilar to those of primary pulmonary alveolar proteinosis.