Sialolithiasis caused by a foreign body is exceedingly rare. We present two cases involving sialolithiasis of the submandibular gland caused by fish bones. Two patients presented with acute sialoadenitis accompanied by sialolithiasis of the submandibular gland. Both patients denied having any history of a fish bone piercing injury. After sialolithotomy, the inflammatory symptoms subsided rapidly. Histopathological study in both cases revealed the presence of a fish bone embedded in the calculi. The two cases confirm that foreign bodies in the salivary system can serve as the nidus of the sialolith.