Mucoceles are often caused by sinus surgery or trauma but rarely by fungus balls. Although the most common location of fungus balls is the maxillary sinus, maxillary sinus mucocele is relatively rare. Therefore, coexistence of a fungus ball and mucocele in the maxillary sinus is extremely rare. We report two cases of fungus balls within mucoceles of the maxillary sinus, together with a literature review.