A 46-year-old Japanese woman has been followed up for 3 years due to interstitial pneumonia associated with progressive systemic sclerosis (PSS). During this follow-up period, chest roentgenogram revealed additional diffuse nodular shadows. She was diagnosed as having pulmonary sarcoidosis, which was confirmed by the presence of epitheloid granulomas within the alveolar septa. She was successfully treated with corticosteroids and recovered almost completely without worsening pulmonary abnormalities caused by her PSS. The independent clinical courses of these two diseases in the present case suggest that the complication of PSS and sarcoidosis in this patient may be coincidental.