A 32-year-old woman noted left lid retraction during pregnancy. Examination revealed unilateral enophthalmos without symptoms of diplopia or sinus disease. Orbital imaging showed characteristic features of the silent sinus syndrome, which were confirmed intraoperatively. The clinical and imaging attributes of this syndrome are discussed, including possible mechanisms of disease development. Management strategies are summarized. A brief discussion of the differential diagnosis of enophthalmos is also included.