Purpose Primary mucinous adenocarcinomas (PMAs) of the eyelid are rare clinical entities typically arising from the peri-orbital area. The purpose of this case-series is to report 3 cases of PMA as well as to discuss the pathological and immunohistochemical features of these tumors. Material & methods Three cases of PMA of the eyelid were identified from 2 tertiary ophthalmology referral centers. Clinical and histopathological features of the cases were reviewed. Immunohistochemistry was performed for cytokeratin (CK) 7, CK20 and p63. Results PMA of the eyelid was identified in the three male patients, ages 63–73 years old. Immunohistochemistry demonstrated positive staining for CK7 and GCDP-15 and were negative for CK20. One of the 3 cases was stained for p63, and it was found to be positive. Conclusion Due to the difficult clinical diagnosis of this often benign appearing lesion, it is imperative that physicians send all specimens for histopathological and immunohistochemical correlation. Advances in IHC including CK7 and CK20 as well as p63 are important for the diagnosis of this rare eyelid tumor, though are not yet totally definitive in their ability to distinguish PMA from other lesions with similar profiles.