Aim: To examine carcinoma ex pleomorphic adenoma (CXPA) and its development to provide information for its clinical assessment and prognosis. Methods: The clinical data of 26 patients with pathologically diagnosed CXPA were included for analysis. The patients' medical histories and data (e.g., gender, age, eye laterality, clinical manifestations, pathologic and immunohistochemical indices, treatments, and prognosis) were recorded. Results: The average age of the 26 patients was 59.6 +/- 15.7y. There was no significant difference in the gender distribution. The incidence of CXPA bone destruction was approximately 57.7%, and the incidence of optic nerve involvement and extraocular muscle involvement was approximately 15.4% and 19.2%, respectively. The most common pathological type was adenocarcinoma (34.6%), followed by ductal carcinoma (26.9%). Five patients had recurrence or metastasis (19.2%). The 5-year recurrence-free survival rate was 59.0%. There were no significant differences in survival rates among patients with different pathologic types and stages (P>0.05). Bone destruction, nerve invasion, and peripheral tissue invasion did not significantly affect survival rate (P>0.05). Surgery combined with I-125 radiation therapy leads to a better survival prognosis (P<0.05). Conclusion: CXPA has a variety of pathologic classifications, with characteristics of bone destruction and peripheral tissue invasion. Surgery combined with I-125 endoradiotherapy is a preferable treatment option. However, long-term follow-up and close observation for recurrence or metastasis should be performed.