Ectopic eruption into the dental environment is common, whereas eruption into other sites is rare. Diverse anatomical locations such as the mandibular condyle, coronoid process, palate, maxillary sinuses and nasal cavity can infrequently be the site of ectopic tooth eruption. One of the nondental sites for ectopic eruption is the maxillary sinus. Here, we present a case of dentigerous cyst with an ectopic maxillary canine tooth located below the floor of the right maxillary sinus in a 37-year-old man.