Lacrimal sac tumours are rare entities. Patients often present with epiphora, recurrent dacryocystitis, and/or a lacrimal sac mass. Neoplasms of the lacrimal system may conveniently be grouped into epithelial and non-epithelial types: papillomas are the most common benign epithelial tumours, while oncocytic adenocarcinomas are extremely rare. Here we report a case of primary oncocytic adenocarcinoma of the lacrimal sac in a 56-year-old man.