Background: Lacrimal drainage system lymphomas are rare, accounting for less than 10% of lacrimal sac tumors. They often appear as a secondary involvement within the confines of systemic lymphoproliferative disorders, therefore detailed ophthalmological examination and auxiliary testing is necessary to have an accurate diagnosis. Case report: We present the case of a 72-year-old woman with a medical history of chronic lymphocytic leukemia and small lymphocytic lymphoma. She presented to the ophthalmology clinic with a painful, discharging swelling in the right lacrimal sac area. Magnetic resonance imaging revealed a mass in the right nasolacrimal duct. A right external dacryocystorhinostomy was performed. The histological findings led to a diagnosis of small lymphocytic lymphoma. Conclusions: Special attention is required in cases of known systemic hematological disorders that associate with nasolacrimal duct obstruction or epiphora. Quick recognition and a full history with multidisciplinary clinical and diagnostic workup are fundamental to plan the treatment.