The incidence of lymphoma is constantly increasing worldwide. The reasons for this increase are unclear and likely multiple. B cell lymphomas represent the majority of non-Hodgkin lymphomas. Primary orbital localization remains a rare entity to think about in order to avoid missing a therapeutic emergency. In this article, we report the case of a 52-year-old man who has been treated for five years for an inflammatory orbitopathy with steroids, but the worsening of the clinical condition and the installation of exophthalmia led to push investigations and the outcome was a primary orbital lymphoma marginal zone type. The patient was treated by systemic chemotherapy with immunotherapy (RCHOP protocol) with a very good evolution and complete disappearance of the lesion after chemotherapy.