The authors report a case of fungus ball of the maxillary sinus with bone erosion presenting with epiphora, which was diagnosed after treatment failure using silicone intubation for nasolacrimal duct obstruction. Symptoms of sinus fungus ball are similar to those of chronic bacterial rhinosinusitis, although occasionally asymptomatic. To our knowledge, epiphora has never been reported as a symptom of sinus fungus ball. The purpose of this report is to emphasize the importance of considering sinonasal causes when evaluating epiphora patients, as well as to suggest the use of preoperative CT scans for a more accurate diagnosis and to prevent unnecessary procedures.