When the juvenile worms of the genus Paragonimus migrate and cause defects on the surface of the visceral pleura, pneumothorax can develop. A 34-year-old woman was admitted for pneumothorax with which was developed after she ate raw fish and crab. A 21-year-old male soldier presented with recurrent bilateral pneumothorax without eosinophilia, caused after drinking stream water frequently. In both patients, paragonimiasis was suspected from the computed tomography scan and confirmed by an enzyme-linked immunosorbent assay test of the pleural fluid. When pneumothorax develops in patients who have ingested raw fresh-water crab or stream water, paragonimiasis should always be considered in the differential diagnosis.