Purpose: Apocrine adenocarcinoma is a cutaneous adnexal malignancy which can rarely arise from ocular structures. In this retrospective study, we report our experience with four patients who had primary periocular apocrine adenocarcinoma initially presenting with an orbital tumor. Methods: Data extracted included demographics, clinical, imaging, and histopathological features, and treatment outcomes. Results: The definitive diagnosis was established after an incisional biopsy in all cases. Two patients were then managed with exenteration. The third patient underwent local resection followed by radiotherapy but had to be exenterated because of new tumor formation 7 years later. The fourth patient had to be managed with oral bicalutamide which kept the tumor stable for 3 years. Recurrence-free survival for the radical surgical treatment group was 10, 6, and 7 years respectively. Conclusion: Periocular apocrine adenocarcinoma may insidiously develop as an orbital mass without any clinically detectable primary eyelid skin or conjunctival lesions. This tumor must be in the differential diagnosis of medially located ill-defined orbital masses in patients over 50 years of age. Orbital exenteration appeared as an effective treatment of apocrine adenocarcinoma with orbital extension. Anti-androgenic treatment in an androgen receptor-positive tumor provided temporary local tumor control.